Note: Descriptions are shown in the official language in which they were submitted.
WO 2023/028070
PCT/US2022/041247
METHODS OF PRODUCING 2XXX ALUMINUM ALLOYS
CROSS-REFERENCE TO RELATED APPLICATION
[001] The present patent application claims priority to U.S. Provisional
Patent Application
No. 63/236,614 entitled "METHODS OF PRODUCING 2XXX ALUMINUM ALLOYS" filed
August 24, 2021, which application is incorporated herein by reference in its
entirety.
BACKGROUND
[002] Aluminum alloys are useful in a variety of applications. However,
improving one
property of an aluminum alloy without degrading another property often proves
elusive. For
example, it is difficult to increase the strength of an alloy without
decreasing the toughness of an
alloy. Other properties of interest for aluminum alloys include corrosion
resistance and fatigue
crack growth rate resistance, to name two.
SUMMARY OF THE DISCLOSURE
[003] Broadly, the present patent application relates to methods of
producing 2xxx aluminum
alloys. In one approach, a method comprises artificially aging a 2xxx aluminum
alloy in at least
two-steps ("two-step artificial aging"). In one embodiment, the artificial
aging comprises (a) first
aging a 2xxx aluminum alloy at a first temperature of from 300 F to 450 F and
for a first aging
time of from 4 to 120 hours, and (b) second aging the 2xxx aluminum alloy at a
second temperature
for a second aging time of from 30 minutes to 120 hours, wherein the second
temperature is from
20 F to 150 F lower than the first temperature. The new two-step artificial
aging step may
facilitate an improved combination of properties, such as an improved
combination of two or more
of strength, ductility, fracture toughness, and corrosion resistance. In one
embodiment, at least
partially due to the first aging and second aging steps, the 2xxx aluminum
alloy is (i) LT stress
corrosion cracking resistant (defined below), (ii) ST stress corrosion
cracking resistant (defined
below), or (iii) both LT stress corrosion cracking resistant and ST stress
corrosion cracking
resistant. Additional details are provided in the sections that follow.
1. Composition
[004] The new methods described herein are applicable to 2xxx aluminum
alloys (defined
below). Some useful 2xxx aluminum alloys include those described in
International Patent
Application Publication No. W02020/123096 A2, filed November 15, 2019 by
Arconic Inc.,
currently assigned to Arconic Technologies LLC.
1
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
[005] In one embodiment, a 2xxx aluminum alloy comprises (and in some
instances consists
essentially of, or consists of) from 0.08 to 0.20 wt. 0/0 Ti, from 4.5 to 5.5
wt. % Cu, from 0.20 to
0.6 wt. % Mn, from 0.20 to 0.8 wt. % Mg, from 0.05 to 0.60 wt. % Ag, up to 1.0
wt. % Zn, up to
0.30 wt. % Fe, up to 0.20 wt. % Si, up to 0.25 wt. 9/0Zr, up to 0.25 wt. % Cr,
and up to 0.25 wt. %
V, the balance being aluminum, incidental elements and impurities. In one
embodiment, the 2xxx
aluminum alloy is a 2039 alloy (as defined by the Aluminum Association Teal
Sheets document,
described below) modified to include 0.08 to 0.20 wt. % Ti, such as any of the
titanium
limits/ranges described below. In one embodiment, the 2xxx aluminum alloy is a
2039 alloy
modified to include 0.08 to 0.20 wt. % Ti and from 0 to 0.10 wt. % Zr. The
teachings of this
paragraph also apply to other 2x39 alloys, such as 2139. The 2xxx aluminum
alloys described
herein may realize an improved combination of at least two of strength,
ductility, fracture
toughness, and corrosion resistance (e.g., stress corrosion cracking
resistance), among others.
[006] As noted above, the 2xxx aluminum alloys generally include 0.08 to
0.20 wt. % Ti.
The use of titanium in combination with other elements of the 2xxx aluminum
alloys may result
in 2xxx aluminum alloys products having an improved combination of properties,
such as an
improved combination of two or more of strength, ductility (elongation),
fracture toughness and
corrosion resistance (e.g., stress corrosion cracking resistance), among
others. The amount of
titanium present in the 2xxx aluminum alloys should be limited such that large
primary particles
do not form in the alloy. In one embodiment, a 2xxx aluminum alloy includes at
least 0.09 wt. %
Ti. In another embodiment, a 2xxx aluminum alloy includes at least 0.10 wt. %
Ti. In yet another
embodiment, a 2xxx aluminum alloy includes at least 0.11 wt. % Ti. In one
embodiment, a 2xxx
aluminum alloy includes not greater than 0.18 wt. % Ti. In another embodiment,
a 2xxx aluminum
alloy includes not greater than 0.16 wt. % Ti. In yet another embodiment, a
2xxx aluminum alloy
includes not greater than 0.15 wt. % Ti. In another embodiment, a 2xxx
aluminum alloy includes
not greater than 0.14 wt. % Ti. In yet another embodiment, a 2xxx aluminum
alloy includes not
greater than 0.13 wt. % Ti. The titanium may facilitate improved stress
corrosion cracking
resistance properties while also facilitating, for instance, grain refining,
among other things.
Titanium may be added as a separate element and/or as part of a grain refining
compound.
Examples of grain refiners include Ti combined with B (e.g., TiB2) or carbon
(TiC), although other
grain refiners, such as Al-Ti master alloys may be utilized. Grain refiners in
combination with
2
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
elemental titanium may be used in the 2xxx aluminum alloys in any appropriate
amount, and
generally depending on the desired as-cast grain size.
[007] As noted above, a 2xxx aluminum alloy may include from 4.5 to 5.5 wt.
% Cu. In one
embodiment, a 2xxx aluminum alloy includes at least 4.6 wt. % Cu. In another
embodiment, a
2xxx aluminum alloy includes at least 4.7 wt. % Cu. In yet another embodiment,
a 2xxx aluminum
alloy includes at least 4.8 wt. % Cu. In one embodiment, a 2xxx aluminum alloy
includes not
greater than 5.4 wt. % Cu. In another embodiment, a 2xxx aluminum alloy
includes not greater
than 5.3 wt. `)/0 Cu. In yet another embodiment, a 2xxx aluminum alloy
includes not greater than
5.2 wt. % Cu. In another embodiment, a 2xxx aluminum alloy includes not
greater than 5.1 wt. %
Cu. In yet another embodiment, a 2xxx aluminum alloy includes not greater than
5.0 wt. % Cu.
[008] As noted above, a 2xxx aluminum alloy may include from 0.20 to 0.6
wt. % Mn. In
one embodiment, a 2xxx aluminum alloy includes at least 0.25 wt. % Mn. In
another embodiment,
a 2xxx aluminum alloy includes at least 0.30 wt. % Mn. In one embodiment, a
2xxx aluminum
alloy includes not greater than 0.55 wt. % Mn. In another embodiment, a 2xxx
aluminum alloy
includes not greater than 0.50 wt. % Mn. In yet another embodiment, a 2xxx
aluminum alloy
includes not greater than 0.45 wt. % Mn. In another embodiment, a 2xxx
aluminum alloy includes
not greater than 0.40 wt. % Mn.
[009] As noted above, a 2xxx aluminum alloy may include from 0.20 to 0.6
wt. % Mg. In
one embodiment, a 2xxx aluminum alloy includes at least 0.25 wt. % Mg. In
another embodiment,
a 2xxx aluminum alloy includes at least 0.30 wt. % Mg. In one embodiment, a
2xxx aluminum
alloy includes not greater than 0.55 wt. % Mg. In another embodiment, a 2xxx
aluminum alloy
includes not greater than 0,50 wt. % Mg.
[0010] As noted above, a 2xxx aluminum alloy may include from 0.05
to 0.6 wt. % Ag. In one
embodiment, a 2xxx aluminum alloy includes at least 0.10 wt. (21/0 Ag. In
another embodiment, a
2xxx aluminum alloy includes at least 0.15 wt. % Ag. In yet another
embodiment, a 2xxx
aluminum alloy includes at least 0.20 wt. % Ag. In another embodiment, a 2xxx
aluminum alloy
includes at least 0.25 wt. % Ag. In yet another embodiment, a 2xxx aluminum
alloy includes at
least 0.30 wt. % Ag. In one embodiment, a 2xxx aluminum alloy includes not
greater than 0.55
wt. % Ag. In another embodiment, a 2xxx aluminum alloy includes not greater
than 0.50 wt. %
Ag. In yet another embodiment, a 2xxx aluminum alloy includes not greater than
0.45 wt. % Ag.
In another embodiment, a 2xxx aluminum alloy includes not greater than 0.40
wt. % Ag.
3
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
[0011] As noted above, a 2xxx aluminum alloy may include up to 1.0
wt. % Zn. In one
embodiment, a 2xxx aluminum alloy includes at least 0.10 wt. % Zn. In another
embodiment, a
2xxx aluminum alloy includes at least 0.20 wt. % Zn. In yet another
embodiment, a 2xxx
aluminum alloy includes at least 0.30 wt. % Zn. In another embodiment, a 2xxx
aluminum alloy
includes at least 0.40 wt. % Zn. In yet another embodiment, a 2xxx aluminum
alloy includes at
least 0.50 wt. % Zn. In one embodiment, a 2xxx aluminum alloy includes not
greater than 0.90
wt. % Zn. In another embodiment, a 2xxx aluminum alloy includes not greater
than 0.80 wt. %
Zn. In yet another embodiment, a 2xxx aluminum alloy includes not greater than
0.70 wt. % Zn.
In another embodiment, a 2xxx aluminum alloy includes not greater than 0.60
wt. % Zn.
[0012] As noted above, a 2xxx aluminum alloy may include up to 0.25
wt. % Zr. In some
embodiments, the combination of both (a) elevated levels of titanium, and (b)
use of zirconium
may facilitate the realization of improved 2xxx aluminum alloy products having
an improved
combination of at least two of strength, elongation, fracture toughness and
corrosion resistance
(e.g., stress corrosion cracking resistance), among others. In one embodiment,
a 2xxx aluminum
alloy includes at least 0.05 wt. % Zr. In another embodiment, a 2xxx aluminum
alloy includes at
least 0.06 wt. % Zr. In yet another embodiment, a 2xxx aluminum alloy includes
at least 0.07 wt.
% Zr. In another embodiment, a 2xxx aluminum alloy includes at least 0.08 wt.
% Zr. In one
embodiment, a 2xxx aluminum alloy includes not greater than 0.18 wt. % Zr. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.16 wt. % Zr. In
yet another
embodiment, a 2xxx aluminum alloy includes not greater than 0.15 wt. % Zr. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.14 wt. % Zr. In
yet another
embodiment, a 2xxx aluminum alloy includes not greater than 0.13 wt. % Zr. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.12 wt. % Zr. In
yet another
embodiment, a 2xxx aluminum alloy includes not greater than 0.11 wt. % Zr. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.10 wt. % Zr. In
yet another
embodiment, a 2xxx aluminum alloy includes not greater than 0.09 wt. % Zr. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.08 wt. % Zr.
[0013] As noted above, a 2xxx aluminum alloy may include up to 0.30
wt. % Fe In one
embodiment, a 2xxx aluminum alloy includes at least 0.01 wt. % Fe. In another
embodiment, a
2xxx aluminum alloy includes at least 0.02 wt. % Fe. In one embodiment, a 2xxx
aluminum alloy
includes not greater than 0.25 wt. % Fe. In another embodiment, a 2xxx
aluminum alloy includes
4
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
not greater than 0.20 wt. % Fe. In yet another embodiment, a 2xxx aluminum
alloy includes not
greater than 0.15 wt. % Fe. In another embodiment, a 2xxx aluminum alloy
includes not greater
than 0.10 wt. % Fe. in yet another embodiment, a 2xxx aluminum alloy includes
not greater than
0.08 wt. % Fe. In another embodiment, a 2xxx aluminum alloy includes not
greater than 0.06 wt.
% Fe. In yet another embodiment, a 2xxx aluminum alloy includes not greater
than 0.04 wt. %
Fe.
[0014] As noted above, a 2xxx aluminum alloy may include up to 0.20
wt. % Si. In one
embodiment, a 2xxx aluminum alloy includes at least 0.01 wt. % Si. In another
embodiment, a
2xxx aluminum alloy includes at least 0.02 wt. % Si. In one embodiment, a 2xxx
aluminum alloy
includes not greater than 0.15 wt. % Si. In another embodiment, a 2xxx
aluminum alloy includes
not greater than 0.10 wt. % Si. In yet another embodiment, a 2xxx aluminum
alloy includes not
greater than 0.07 wt. % Si. In another embodiment, a 2xxx aluminum alloy
includes not greater
than 0.05 wt. % Si. In yet another embodiment, a 2xxx aluminum alloy includes
not greater than
0.03 wt. % Si.
[0015] As noted above, a 2xxx aluminum alloy may include up to 0.25
wt. % Cr. In one
embodiment, a 2xxx aluminum alloy includes not greater than 0.20 wt. % Cr. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.15 wt. % Cr. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.10 wt. % Cr. In
yet another
embodiment, a 2xxx aluminum alloy includes not greater than 0.05 wt. % Cr. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.03 wt. % Cr. In
yet another
embodiment, a 2xxx aluminum alloy includes not greater than 0.01 wt. % Cr.
[0016] As noted above, a 2xxx aluminum alloy may include up to 0.25
wt. % V. In one
embodiment, a 2xxx aluminum alloy includes not greater than 0.20 wt. % V. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.15 wt. % V. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.10 wt. % V. In
yet another
embodiment, a 2xxx aluminum alloy includes not greater than 0.05 wt. % V. In
another
embodiment, a 2xxx aluminum alloy includes not greater than 0.03 wt. % V. In
yet another
embodiment, a 2xxx aluminum alloy includes not greater than 0.01 wt. % V.
[0017] Some embodiments of useful alloys in accordance with the
present disclosure are
provided below (all values in weight percent).
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
Alloy Cu Mn Mg Zn Ag Ti
A 4.5 - 5.5 0.20 - 0.60 0.20 - 0.60 0.10- 1.0 ..
0.05 -0.60 .. 0.08 -0.20
4.6 - 5.4 0.20 - 0.55 0.25 - 0.55 0.20- 0.80 0.10
- 0.55 0.08- 0.18
4.7- 5.3 0.25 -0.50 0.30 - 0.55 0.30 - 0.70
0.15 -0.50 0.08 -0.16
4.8- 5.2 0.25 -0.45 0.35 -0.55 0.30 - 0.60
0.20 - 0.45 0.08 -0.15
4.8- 5.1 0.25 -0.40 0.35 -0.50 0.40 -0.60 0.25
-0.40 0.08 - 0.14
4.8 - 5.0 0.30 - 0.40 0.40 - 0.50 0.40- 0.60 0.30
- 0.40 0.08 -0.13
Alloy
Zr Fe Si Cr V Balance
(cont.)
A <0.25 <0.30 <0.25 <0.25 <0.25
Aluminum,
0.05-0.18 0.01 -0.25 0.01 -0.25 <0.15 <0.15
incidental
0.05-0.16 0.01 -0.20 0.01 -0.20 <0.10 <0.10
elements
0.06-0.14 0.01 -0.15 0.01 -0.15 < 0.05 < 0.05 and
0.07-0.13 0.02 - 0.10 0.02 - 0.10 < 0.03 < 0.03
impurities.
0.08-0.12 0.02 - 0.08 0.02 - 0.07 < 0.03 < 0.03
[0018] As noted above, in one approach, the 2xxx aluminum alloy is
a 2039 aluminum alloy
modified to include 0.08 to 0.20 wt. % Ti, such as any of the titanium
limits/ranges described
above. Per the Aluminum Association Teal Sheets (2015), a 2039 aluminum alloy
comprises 4.5
to 5.5 wt. % Cu, 0.20 to 0.50 wt. % Mn, 0.40 to 0.8 wt. % Mg, 0.05 to 0.50 wt.
% Ag, 0.10 to 0.25
wt. % Zr, up to 0.20 wt. % Si, up to 0.30 wt. % Fe, up to 0.15 wt. % Ti, the
balance being aluminum,
incidental elements and impurities, wherein the 2xxx aluminum alloy includes
not greater than
0.15 wt. %, in total, of the impurities, and wherein the 2xxx aluminum alloy
includes not greater
than 0.05 wt. % of each of the impurities.
[0019] As noted above, in one approach, the 2xxx aluminum alloy is
a 2139 aluminum alloy
modified to include 0.08 to 0.20 wt. % Ti, such as any of the titanium
limits/ranges described
above. Per the Aluminum Association Teal Sheets (2015), a 2139 aluminum alloy
comprises 4.5
to 5.5 wt. % Cu, 0.20 to 0.6 wt. % Mn, 0.20 to 0.8 wt. % Mg, 0.15 to 0.60 wt.
% Ag, up to 0.10
wt. % Si, up to 0.15 wt. % Fe, up to 0.05 wt. % Cr, up to 0.25 wt. % Zn, up to
0.15 wt. % Ti, up
to 0.05 wt. % V, the balance being aluminum, incidental elements and
impurities, wherein the
2xxx aluminum alloy includes not greater than 0.15 wt. %, in total, of the
impurities, and wherein
the 2xxx aluminum alloy includes not greater than 0.05 wt. % of each of the
impurities.
[0020] In one embodiment, a 2039 aluminum alloy or 2139 aluminum
alloy is modified to
include from 0.08 to 0.20 wt. % Ti, such as any of the titanium limits/ranges
described above ("a
6
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
modified 2039/2139 aluminum alloy"), and is further modified to include zinc
(Zn). In one
embodiment, a modified 2039/2139 aluminum alloy includes from 0.08 to 0.20 wt.
% Ti and
includes from 0.10 to 1.0 wt. % Zn. In one embodiment, a modified 2039/2139
aluminum alloy
includes at least 0.20 wt. % Zn. In another embodiment, a modified 2039/2139
aluminum alloy
includes at least 0.30 wt. % Zn. In another embodiment, a modified 2039/2139
aluminum alloy
includes at least 0.40 wt. % Zn. In another embodiment, a modified 2039/2139
aluminum alloy
includes at least 0.50 wt. % Zn. In one embodiment, a modified 2039/2139
aluminum alloy
includes not greater than 0.90 wt. % Zn. In another embodiment, a modified
2039/2139 aluminum
alloy includes not greater than 0.80 wt. % Zn. In another embodiment, a
modified 2039/2139
aluminum alloy includes not greater than 0.70 wt. % Zn. In another embodiment,
a modified
2039/2139 aluminum alloy includes not greater than 0.60 wt. % Zn.
[0021] In one embodiment, a 2039/2139 aluminum alloy is modified to
include from 0.08 to
0.20 wt. % Ti, such as any of the titanium limits/ranges described above ("a
modified 2139
aluminum alloy"), and is further modified to include appropriate amounts of
zirconium. (2039, as
specified by the Aluminum Association Teal Sheets, includes 0.10 - 0.25 wt. %
Zr, and 2139, as
specified by the Aluminum Association Teal Sheets, includes zirconium as an
impurity only.) The
combination of both (a) elevated levels of titanium, and (b) use of zirconium
may facilitate the
realization of improved 2039/2139 aluminum alloy products having an improved
combination of
at least two of strength, elongation, fracture toughness and corrosion
resistance (e.g., stress
corrosion cracking resistance), among others. In one embodiment, a modified
2039/2139
aluminum alloy includes from 0.05 to 0.20 wt. % Zr. In one embodiment, a
modified 2039/2139
aluminum alloy includes at least 0.06 wt. % Zr. In another embodiment, a
modified 2039/2139
aluminum alloy includes at least 0.07 wt. % Zr. In yet another embodiment, a
modified 2039/2139
aluminum alloy includes at least 0.08 wt. % Zr. In one embodiment, a modified
2039/2139
aluminum alloy includes not greater than 0.18 wt. % Zr. In another embodiment,
a modified
2039/2139 aluminum alloy includes not greater than 0.16 wt. % Zr. In another
embodiment, a
modified 2039/2139 aluminum alloy includes not greater than 0.15 wt. % Zr. In
yet another
embodiment, a modified 2039/2139 aluminum alloy includes not greater than 0.14
wt. % Zr. In
another embodiment, a modified 2039/2139 aluminum alloy includes not greater
than 0.13 wt. %
Zr. In another embodiment, a modified 2039/2139 aluminum alloy includes not
greater than 0.12
wt. % Zr. In another embodiment, a modified 2039/2139 aluminum alloy includes
not greater than
7
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
0.11 wt. % Zr. In yet another embodiment, a modified 2039/2139 aluminum alloy
includes not
greater than 0.10 wt. % Zr. In another embodiment, a modified 2039/2139
aluminum alloy
includes not greater than 0.09 wt. % Zr. In another embodiment, a modified
2039/2139 aluminum
alloy includes not greater than 0.08 wt. % Zr. In one embodiment, a modified
2039/2139
aluminum alloy includes from 0.05 wt. % to 0.15 wt. % Zr. In another
embodiment, a modified
2039/2139 aluminum alloy includes from 0.07 wt. % to 0.14 wt. % Zr. In another
embodiment, a
modified 2039/2139 aluminum alloy includes from 0.08 wt. % to 0.13 wt. % Zr.
The amount of
zirconium present in the 2xxx aluminum alloys should be limited such that
large primary particles
do not form in the alloy.
[0022] In one embodiment, a 2139 aluminum alloy is modified to
include from 0.08 to 0.20
wt. % Ti, such as any of the titanium limits/ranges described above ("a
modified 2139 aluminum
alloy"), and is further modified to include zirconium, such as any of the
zirconium limits/ranges
described above, and is further modified to include zinc, such as any of the
zinc limits/ranges
described above.
[0023] As noted above, the alloys generally include the stated
alloying ingredients, the balance
being aluminum, optional incidental elements, and impurities. As used herein,
"incidental
elements" means those elements or materials, other than the above listed
elements, that may
optionally be added to the alloy to assist in the production of the alloy.
Examples of incidental
elements include casting aids, such as grain refiners and deoxidizers.
Optional incidental elements
may be included in the alloy in a cumulative amount of up to 1.0 wt. %. As one
non-limiting
example, one or more incidental elements may be added to the alloy during
casting to reduce or
restrict (and in some instances eliminate) ingot cracking due to, for example,
oxide fold, pit and
oxide patches. These types of incidental elements are generally referred to
herein as deoxidizers.
Examples of some deoxidizers include Ca, Sr, and Be. When calcium (Ca) is
included in the alloy,
it is generally present in an amount of up to 0.05 wt. %, or up to 0.03 wt. %
In some embodiments,
Ca is included in the alloy in an amount of 0.001-0.03 wt. % or 0.05 wt. %,
such as 0.001-0.008
wt. % (or 10 to 80 ppm). Strontium (Sr) may be included in the alloy as a
substitute for Ca (in
whole or in part), and thus may be included in the alloy in the same or
similar amounts as Ca
Traditionally, beryllium (Be) additions have helped to reduce the tendency of
ingot cracking,
though for environmental, health and safety reasons, some embodiments of the
alloy are
substantially Be-free. When Be is included in the alloy, it is generally
present in an amount of up
8
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
to 20 ppm. Incidental elements may be present in minor amounts, or may be
present in significant
amounts, and may add desirable or other characteristics on their own without
departing from the
alloy described herein, so long as the alloy retains the desirable
characteristics described herein. It
is to be understood, however, that the scope of this disclosure should
not/cannot be avoided
through the mere addition of an element or elements in quantities that would
not otherwise impact
on the combinations of properties desired and attained herein.
[0024] The 2xxx aluminum alloys generally contain low amounts of
impurities. In one
embodiment, a 2xxx aluminum alloy includes not greater than 0.15 wt. %, in
total, of the
impurities, and wherein the 2xxx aluminum alloy includes not greater than 0.05
wt. % of each of
the impurities. In another embodiment, a 2xxx aluminum alloy includes not
greater than 0.10 wt.
%, in total, of the impurities, and wherein the 2xxx aluminum alloy includes
not greater than 0.03
wt. % of each of the impurities.
ii. Product Forms
[0025] The new alloys may be useful in a variety of product forms,
including ingot or billet,
wrought product forms (plate, forgings and extrusions), shape castings,
additively manufactured
products, and powder metallurgy products, for instance.
[0026] In one embodiment, a new 2xxx aluminum alloy is in the form
of a thick wrought
product. Thick wrought aluminum alloy products are those wrought products
having a cross-
sectional thickness of at least 12.7 mm. The wrought products may be rolled
products, forged
products or extruded products. In one embodiment, a thick wrought aluminum
alloy product has
a thickness of at least 25 mm. In another embodiment, a thick wrought aluminum
alloy product
has a thickness of at least 38 mm. In yet another embodiment, a thick wrought
aluminum alloy
product has a thickness of at least 50 mm. In another embodiment, a thick
wrought aluminum alloy
product has a thickness of at least 76 mm. In yet another embodiment, a thick
wrought aluminum
alloy product has a thickness of at least 102 mm, or higher.
[0027] The improved properties described herein may be achieved
with thick wrought
products having a thickness of up to 305 mm In one embodiment, a thick wrought
aluminum
alloy product has a thickness of not greater than 254 mm. In another
embodiment, a thick wrought
aluminum alloy product has a thickness of not greater than 203 mm. In yet
another embodiment,
a thick wrought aluminum alloy product has a thickness of not greater than 17S
mm In another
9
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
embodiment, a thick wrought aluminum alloy product has a thickness of not
greater than 152 mm.
As used in this paragraph, thickness refers to the minimum thickness of the
product, realizing that
some portions of the product may realize slightly larger thicknesses than the
minimum stated.
[0028] In another approach, a new 2xxx aluminum alloy is a thin
wrought product having a
thickness of less than 12.7 mm. Thin wrought products have a thickness of less
than 12.7 mm. In
one embodiment, a thin wrought product has a thickness of from 0.5 mm to 12.6
mm. In another
embodiment, a thin wrought product has a thickness of from 1.0 mm to 12.6 mm.
In yet another
embodiment, a thin wrought product has a thickness of from 2.0 mm to 12.6 mm.
In another
embodiment, a thin wrought product has a thickness of from 3.0 mm to 12.6 mm.
In yet another
embodiment, a thin wrought product has a thickness of from 4.0 mm to 12.6 mm.
In another
embodiment, a thin wrought product has a thickness of from 5.0 mm to 12.6 mm.
In yet another
embodiment, a thin wrought product has a thickness of from 6.0 mm to 12.6 mm.
In another
embodiment, a thin wrought product has a thickness of from 7.0 mm to 12.6 mm.
In yet another
embodiment, a thin wrought product has a thickness of from 8.0 mm to 12.6 mm.
iii. Methods ofMaking
[0029] As noted above, new methods of producing 2xxx aluminum
alloys are disclosed. In
one approach, a method comprises artificially aging a 2xxx aluminum alloy in
at least two-steps
("two-step artificial aging"). As shown below, 2xxx aluminum alloys aged using
a first step aging
practice of 350 F for 24 hours and a second step aging practice of 270 F for
24 hours realized an
unexpected combination of at least two of strength, ductility, fracture
toughness, and corrosion
resistance. As appreciated by those skilled in the art, aging temperatures
and/or times may be
adjusted based on well-known aluminum alloy aging principles and/or formulas.
Thus, those
skilled in the art could increase the aging temperature but decrease the aging
time, or vice-versa,
or only slightly change only one of these parameters and still achieve the
same result as aging at
350 F for 24 hours and then at 270 F for 24 hours. Accordingly, some
embodiments disclosed
herein are directed to first artificially aging at 350 F for 24 hours, or a
substantially equivalent
artificial aging temperature and duration, and second artificially aging at
270 F for 24 hours, or a
substantially equivalent artificial aging temperature and duration. The amount
of artificial aging
practices that could achieve the same result as this specific practice is
numerous, and therefore all
such substitute aging practices are not listed herein, even though they are
within the scope of the
present invention. The use of the phrase "or a substantially equivalent
artificial aging temperature
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
and duration" or the phrase "or a substantially equivalent practice" is used
to capture all such
substitute aging practices. As may be appreciated, these substitute artificial
aging steps can occur
in one or multiple steps, and at one or multiple temperatures. That is,
multiple sub-steps may be
used to accomplish the first aging step and/or the second aging step, which
sub-steps may include
age integration. In one embodiment, the artificial aging practice consists
only of two-steps, i.e.,
no additional artificial aging steps are completed after the second artificial
aging step.
[0030] In one approach, an artificial aging practice comprises (a)
first aging a 2xxx aluminum
alloy at a first temperature of from 300 F to 450 F and for a first aging time
of from 4 to 120 hours,
and (b) second aging the 2xxx aluminum alloy at a second temperature for a
second aging time of
from 30 minutes to 120 hours, wherein the second temperature is from 20 F to
150 F lower than
the first temperature. In one embodiment, at least partially due to the first
aging and second aging
steps, the 2xxx aluminum alloy is (i) LT stress corrosion cracking resistant
(defined below), (ii)
ST stress corrosion cracking resistant (defined below), or (iii) both LT
stress corrosion cracking
resistant and ST stress corrosion cracking resistant.
[0031] As noted above, the first step of the artificial aging
process generally comprises aging
the 2xxx aluminum alloy at a first temperature for a first period of time,
such as from 300 F to
450 F and for a first aging time of from 4 to 120 hours. In one embodiment,
the first temperature
is at least 310 F. In another embodiment, the first temperature is at least
320 F. In yet another
embodiment, the first temperature is at least 330 F. In another embodiment,
the first temperature
is at least 340 F. In yet another embodiment, the first temperature is at
least 350 F. In one
embodiment, the first temperature is not greater than 440 F. In another
embodiment, the first
temperature is not greater than 430 F. In yet another embodiment, the first
temperature is not
greater than 420 F. In another embodiment, the first temperature is not
greater than 410 F. In yet
another embodiment, the first temperature is not greater than 400 F. In
another embodiment, the
first temperature is not greater than 390 F. In yet another embodiment, the
first temperature is not
greater than 380 F. In another embodiment, the first temperature is not
greater than 370 F. In one
embodiment, the first period of time of the first artificial aging step (i.e.,
the first aging time) is at
least 8 hours In another embodiment, the first aging time is at least 12 hours
In yet another
embodiment, the first aging time is at least 16 hours In another embodiment,
the first aging time
is at least 20 hours. In yet another embodiment, the first aging time is at
least 24 hours. In one
embodiment, the first aging time is not greater than 96 hours. In another
embodiment, the first
11
CA 03227929 2024- 2-2
WO 2023/028070
PCT/ITS2022/041247
aging time is not greater than 72 hours. In yet another embodiment, the first
aging time is not
greater than 48 hours. In another embodiment, the first aging time is not
greater than 40 hours. In
yet another embodiment, the first aging time is not greater than 36 hours. In
another embodiment,
the first aging time is not greater than 32 hours. In yet another embodiment,
the first aging time is
not greater than 28 hours.
[0032] In one embodiment, the first temperature is from 330 F to
370 F and the first aging
time is from 12 to 36 hours.
[0033] In one approach, the amount of time of the first step is
determined according to an
equivalent time at 350 F. In this approach, the first step time (ti'al) is in
accordance with the
below formula:
t350 F eq. actual 156000 1 1
1 = t1 * exp
8.314 * 5 "F 5
g
wherein (a) T;F is the actual temperature of the first step in Fahrenheit,
wherein T;Fis from 300 to
450 F, (b) tactual is the actual amount of time at the first temperature,
wherein ti'ctuth is from 10 to
120 hours, and (c) ti30 F eq. is the equivalent amount of time at a first step
temperature of 350 F.
[0034] In one approach, t135" eq- is from 20 to 30 hours. In one
embodiment, t13501. eq- is at
least 20.5 hours. In another embodiment, t13500Feq- is at least 21 hours. In
yet another embodiment,
t135wF eq- is at least 21.5 hours. In another embodiment, t13'"'q- is at least
22 hours. In yet another
embodiment, t1350Feq. is at least 22.5 hours. In another embodiment, t1350T eq-
is at least 23 hours.
In yet another embodiment, ti35 T eq. is at least 23.5 hours. In another
embodiment, ti350T eq. is at
least 24 hours. In one embodiment, t13500F eq- is not greater than 29 hours.
In another embodiment,
ti35 F eq- is not greater than 28 hours. In yet another embodiment, ti35 'F
eq- is not greater than 27
hours. In another embodiment, t1350 F' eq. is not greater than 26 hours. In
yet another embodiment,
ti35wF eq- is not greater than 25 hours. In another embodiment, t135" eq- is
not greater than 24.5
hours. In yet another embodiment, t1350 Fcq. is not greater than 24 hours. In
one embodiment, t1350 F
'I- is from 20.5 to 24 hours. In another embodiment, t135" eq- is from 21 to
24 hours. In another
embodiment, t1350 ' eq. is from 21.5 to 24 hours. In yet another embodiment,
t1350 F eq- is from 22 to
24 hours. In another embodiment, t135" eq is from 22.5 to 24 hours.
12
CA 03227929 2024- 2-2
WO 2023/028070
PCT/ITS2022/041247
[0035] As noted above, the second step of the artificial aging
process generally comprises
aging the 2xxx aluminum alloy at a second temperature for a second period of
time, such as at a
temperature that is at least 20 F lower than, but not more than 150 F lower
than, the first aging
temperature and for a period of time of from 30 minutes to 120 hours. For
instance, if the first
aging temperature is 350 F, the second aging temperature would be no higher
than 330 F (i.e.,
20 F lower than the first temperature), but the second aging temperature would
be at least 200 F
(i.e., not more than 150 F lower than the first aging temperature).
[0036] In one embodiment, the second temperature is at least at
least 30 F lower than the first
temperature In another embodiment, the second temperature is at least 40 F
lower than the first
temperature. In yet another embodiment, the second temperature is at least 50
F lower than the
first temperature. In another embodiment, the second temperature is at least
60 F lower than the
first temperature. In yet another embodiment, the second temperature is at
least 70 F lower than
the first temperature. In another embodiment, the second temperature is at
least 80 F lower than
the first temperature. In one embodiment, the second temperature is not
greater than 140 F lower
than the first temperature. In another embodiment, the second temperature is
not greater than
130 F lower than the first temperature. In yet another embodiment, the second
temperature is not
greater than 120 F lower than the first temperature. In another embodiment,
the second
temperature is not greater than 110 F lower than the first temperature. In yet
another embodiment,
the second temperature is not greater than 100 F lower than the first
temperature.
[0037] In one embodiment, the second period of time of the second
artificial aging step (i.e.,
the second aging time) is at least 8 hours. In another embodiment, the second
aging time is at least
12 hours. In yet another embodiment, the second aging time is at least 16
hours. In another
embodiment, the second aging time is at least 20 hours. In yet another
embodiment, the second
aging time is at least 24 hours. In one embodiment, the second aging time is
not greater than 96
hours. In another embodiment, the second aging time is not greater than 72
hours. In yet another
embodiment, the second aging time is not greater than 48 hours. In another
embodiment, the
second aging time is not greater than 40 hours. In yet another embodiment, the
second aging time
is not greater than 36 hours In another embodiment, the second aging time is
not greater than 32
hours. In yet another embodiment, the second aging time is not greater than 28
hours.
[0038] In one embodiment, the second aging temperature is from 250
to 290 F and the second
aging time is from 12 to 36 hours.
13
CA 03227929 2024- 2-2
WO 2023/028070
PCT/ITS2022/041247
[0039] The two-step aging practices described herein may be
conducted in a conventional
fashion, such as by the use of temperature controlled furnaces. In one
embodiment, after the first
aging step, the 2xxx aluminum alloy is allowed to cool to room temperature
(e.g., by turning off
the furnace and/or removing the material from the furnace, after which the
material is allowed to
cool to room temperature.) The material may then be reheated from room
temperature to complete
the second aging step, e.g., reheated to the second temperature of the second
aging step.
[0040] In another embodiment, the material is cooled from the first
temperature to the second
temperature. In this embodiment, the furnace set-point may be changed and/or
the furnace may
be turned off and allowed to cool to the second temperature, after which the
second aging step is
initiated (e.g., due to achievement of the second temperature). In this
embodiment, cooling below
the second step is not completed.
[0041] Variations of the above may also be practiced where the
material is allowed to cool
somewhat below the second temperature, but not all the way to room
temperature, and such
variations are within the scope of the present disclosure.
[0042] In one embodiment, a method comprises preparing a 2xxx
aluminum alloy for artificial
aging. The preparing step may include, for instance, casting a 2xxx aluminum
alloy into an ingot
or billet (e.g., via direct chill (DC) casting). After conventional scalping,
lathing or peeling (if
needed) and homogenization, which homogenization may be completed before or
after scalping,
the ingots/billets may be further processed by hot working the product. The
product may then be
optionally cold worked, solution heat treated, quenched, and final cold worked
(e.g., by stretching
or compression of from 0.5% to 15%). After the final cold working step, the
product may be
artificially aged, as provided above. Thus, in some embodiments, the products
may be produced
in a T3 or T8 temper. In other embodiments, other T tempers may be used (e.g.,
any of a Ti, T2,
T4, T5, T6, T7 or T9 temper). T tempers are defined in ANSI H35.1 (2009).
[0043] In some embodiments, forming operations may be completed
concomitant to artificial
aging, for instance, by forming the alloy into a predetermined shaped product
before artificial
aging, during artificial aging, after artificial aging, and combinations
thereof. In such cases, the
accumulated amount of cold work completed after solution heat treatment may be
higher, such as
from 10-15% cold work, or more.
14
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
[0044] As noted above, as part of processing to a T temper, the
wrought product may be
solution heat treated and then optionally cold worked, such as by stretching.
In one approach, a
wrought product is processed to a T temper and part of that processing
includes stretching by from
0.5 to 10% after solution heat treatment. As shown by the below examples, in
some instances,
appropriate amounts of stretch may facilitate realization of an improved
combination of properties,
such as an improved combination of two or more of strength, ductility,
fracture toughness and
corrosion resistance (e.g., stress corrosion cracking resistance) properties.
In one embodiment, a
wrought product is stretched at least 1% after solution heat treatment. In
another embodiment, a
wrought product is stretched at least 1.5% after solution heat treatment. In
yet another
embodiment, a wrought product is stretched at least 2% after solution heat
treatment. In one
embodiment, a wrought product is stretched not greater than 9% after solution
heat treatment. In
another embodiment, a wrought product is stretched not greater than 8% after
solution heat
treatment.
iv. Properties
[0045] The new 2xxx aluminum alloys generally realize an improved
combination of at least
two of strength, elongation, fracture toughness, and corrosion resistance
(e.g., stress corrosion
cracking resistance).
[0046] For purposes of this patent application, the "T8 temper" is
per ANSI H35.1(2009), and
includes all artificial aging conditions, including underaged, peak or near
peak aged, and overaged
aging conditions.
[0047] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes a tensile yield strength (L) of at least 390 MPa in the T8
temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes a tensile
yield strength (L) of at least 400 MPa in the T8 temper. In yet another
embodiment, a new 2xxx
aluminum alloy has a thickness of at least 12.7 mm and realizes a tensile
yield strength (L) of at
least 410 MPa in the T8 temper. In another embodiment, a new 2xxx aluminum
alloy has a
thickness of at least 12.7 mm and realizes a tensile yield strength (L) of at
least 420 MPa in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a tensile yield strength (L) of at least 430 MPa in the T8
temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes a tensile
yield strength (L) of at least 440 MPa in the T8 temper. In yet another
embodiment, a new 2xxx
CA 03227929 2024- 2-2
WO 2023/028070
PCT/ITS2022/041247
aluminum alloy has a thickness of at least 12.7 mm and realizes a tensile
yield strength (L) of at
least 450 MPa in the T8 temper. In another embodiment, a new 2xxx aluminum
alloy has a
thickness of at least 12.7 mm and realizes a tensile yield strength (L) of at
least 460 MPa, or more,
in the T8 temper. The above strength properties may be realized in products
having a thickness of
at least 25 mm, or at least 38 mm, or at least 50 mm, or at least 76 mm, or at
least 108 mm, or
higher. The above strength properties may be realized in thin wrought products
having a thickness
of 0.5 to 12.6 mm.
[0048] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 30 MPa-
sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (L-T) of at least 31 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 32
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 33 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (KT) fracture toughness (L-T) of at least 34
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (L-T) of at least 35 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 36
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 37 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 38
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (L-T) of at least 39 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (KT) fracture toughness (L-T) of at least 40
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 41 MPa-
sqrt-m in the T8
16
CA 03227929 2024- 2-2
WO 2023/028070
PCT/ITS2022/041247
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 42
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 43 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 44
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 45 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 46
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (L-T) of at least 47 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kr) fracture toughness (L-T) of at least 48
WiPa-sqrt-m in the T8
tcmper. In anothcr cmbodimcnt, a ncw 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (L-T) of at least 49 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (KT) fracture toughness (L-T) of at least 50
MPa-sqrt-m, or more,
in the T8 temper. The above fracture toughness properties may be realized in
products having a
thickness of at least 25 mm, or at least 38 mm, or at least 50 mm, or at least
76 mm, or at least 108
mm, or higher. The above fracture toughness properties may be realized in thin
wrought products
having a thickness of 0.5 to 12.6 min.
[0049] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes an elongation (L) of at least 6.0% in the T8 temper. In another
embodiment, a new
2xxx aluminum alloy has a thickness of at least 12.7 mm and realizes an
elongation (L) of at least
8.0% in the T8 temper. In yet another embodiment, a new 2xxx aluminum alloy
has a thickness
of at least 12.7 mm and realizes an elongation (L) of at least 10.0% in the T8
temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes an
elongation (L) of at least 12.0% in the T8 temper. In yet another embodiment,
a new 2xxx
aluminum alloy has a thickness of at least 12.7 mm and realizes an elongation
(L) of at least 14.0%
in the T8 temper. In another embodiment, a new 2xxx aluminum alloy has a
thickness of at least
17
CA 03227929 2024- 2-2
WO 2023/028070
PCT/ITS2022/041247
12.7 mm and realizes an elongation (L) of at least 16.0%, or more, in the T8
temper. The above
elongation properties may be realized in products having a thickness of at
least 25 mm, or at least
38 mm, or at least 50 mm, or at least 76 mm, or at least 108 mm, or higher.
The above elongation
properties may be realized in thin wrought products having a thickness of 0.5
to 12.6 mm.
[0050] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes a tensile yield strength (LT) of at least 390 MPa in the T8
temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes a tensile
yield strength (LT) of at least 400 MPa in the T8 temper. In yet another
embodiment, a new 2xxx
aluminum alloy has a thickness of at least 12.7 mm and realizes a tensile
yield strength (LT) of at
least 410 MPa in the T8 temper. In another embodiment, a new 2xxx aluminum
alloy has a
thickness of at least 12.7 mm and realizes a tensile yield strength (LT) of at
least 420 MPa in the
T8 temper. In yet another embodiment, a new 2xxx aluminum alloy has a
thickness of at least 12.7
mm and realizes a tensile yield strength (LT) of at least 430 lVfPa in the T8
temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes a tensile
yield strength (LT) of at least 440 MPa in the T8 temper. In yet another
embodiment, a new 2xxx
aluminum alloy has a thickness of at least 12.7 mm and realizes a tensile
yield strength (LT) of at
least 450 MPa in the T8 temper. In another embodiment, a new 2xxx aluminum
alloy has a
thickness of at least 12.7 mm and realizes a tensile yield strength (LT) of at
least 460 MPa, or
more, in the T8 temper. The above strength properties may be realized in
products having a
thickness of at least 25 mm, or at least 38 mm, or at least 50 mm, or at least
76 mm, or at least 108
mm, or higher. The above strength properties may be realized in thin wrought
products having a
thickness of 0.5 to 12.6 mm.
[0051] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (T-L) of at least 30 MPa-
sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 31 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 32
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (T-L) of at least 33 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
18
CA 03227929 2024- 2-2
WO 2023/028070
PCT/ITS2022/041247
mm and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 34
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 35 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kw) fracture toughness (T-L) of at least 36
NiPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (T-L) of at least 37 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 38
NiPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (T-L) of at least 39 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 40
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (T-L) of at least 41 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 42
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 43 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 44
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (T-L) of at least 45 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kfc) fracture toughness (T-L) of at least 46
I\SPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (T-L) of at least 47 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (KT) fracture toughness (T-L) of at least 48
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 49 MPa-
sqrt-m in the T8
19
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (T-L) of at least 50
MPa-scirt-m, or more,
in the T8 temper. The above fracture toughness properties may be realized in
products having a
thickness of at least 25 mm, or at least 38 mm, or at least 50 mm, or at least
76 mm, or at least 108
mm, or higher. The above fracture toughness properties may be realized in thin
wrought products
having a thickness of 0.5 to 12.6 mm.
[0052] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes an elongation (LT) of at least 6.0% in the T8 temper. In another
embodiment, a new
2xxx aluminum alloy has a thickness of at least 12.7 mm and realizes an
elongation (LT) of at least
8.0% in the T8 temper. In yet another embodiment, a new 2xxx aluminum alloy
has a thickness
of at least 12.7 mm and realizes an elongation (LT) of at least 10.0% in the
T8 temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes an
elongation (LT) of at least 12.0% in the T8 temper. In yet another embodiment,
a new 2xxx
aluminum alloy has a thickness of at least 12.7 mm and realizes an elongation
(LT) of at least
14.0% in the T8 temper. In another embodiment, a new 2xxx aluminum alloy has a
thickness of
at least 12.7 mm and realizes an elongation (LT) of at least 16.0%, or more,
in the T8 temper. The
above elongation properties may be realized in products having a thickness of
at least 25 mm, or
at least 38 mm, or at least 50 mm, or at least 76 mm, or at least 108 mm, or
higher. The above
elongation properties may be realized in thin wrought products having a
thickness of 0.5 to 12.6
mm.
[0053] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes a tensile yield strength (ST) of at least 350 MPa in the T8
temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes a tensile
yield strength (ST) of at least 360 MPa in the T8 temper. In yet another
embodiment, a new 2xxx
aluminum alloy has a thickness of at least 12.7 mm and realizes a tensile
yield strength (ST) of at
least 370 MPa in the T8 temper. In another embodiment, a new 2xxx aluminum
alloy has a
thickness of at least 12.7 mm and realizes a tensile yield strength (ST) of at
least 380 MPa in the
T8 temper. In yet another embodiment, a new 2xxx aluminum alloy has a
thickness of at least 12.7
mm and realizes a tensile yield strength (ST) of at least 390 MPa in the T8
temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes a tensile
yield strength (ST) of at least 400 MPa in the T8 temper. In yet another
embodiment, a new 2xxx
CA 03227929 2024- 2-2
WO 2023/028070
PCT/ITS2022/041247
aluminum alloy has a thickness of at least 12.7 mm and realizes a tensile
yield strength (ST) of at
least 410 MPa in the T8 temper. In another embodiment, a new 2xxx aluminum
alloy has a
thickness of at least 12.7 mm and realizes a tensile yield strength (ST) of at
least 420 MPa, or
more, in the T8 temper. The above strength properties may be realized in
products having a
thickness of at least 25 mm, or at least 38 mm, or at least 50 mm, or at least
76 mm, or at least 108
mm, or higher. The above strength properties may be realized in thin wrought
products having a
thickness of 7.0 to 12.6 mm.
[0054] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 30 MPa-
sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (S-L) of at least 31 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Km.) fracture toughness (S-L) of at least 32
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 33 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (KT) fracture toughness (S-L) of at least 34
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (S-L) of at least 35 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 36
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 37 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 38
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (S-L) of at least 39 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Km) fracture toughness (S-L) of at least 40
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 41 MPa-
sqrt-m in the T8
21
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 42
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 43 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 44
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 45 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kic) fracture toughness (S-L) of at least 46
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (S-L) of at least 47 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (Kr) fracture toughness (S-L) of at least 48
MPa-sqrt-m in the T8
temper. In another embodiment, a new 2xxx aluminum alloy has a thickness of at
least 12.7 mm
and realizes a plane-strain (Kw) fracture toughness (S-L) of at least 49 MPa-
sqrt-m in the T8
temper. In yet another embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7
mm and realizes a plane-strain (KT) fracture toughness (S-L) of at least 50
MPa-sqrt-m, or more,
in the T8 temper. The above fracture toughness properties may be realized in
products having a
thickness of at least 25 mm, or at least 38 mm, or at least 50 mm, or at least
76 mm, or at least 108
mm, or higher. The above fracture toughness properties may be realized in thin
wrought products
haying a thickness of 7.0 to 12.6 min.
[0055] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and realizes an elongation (ST) of at least 3.0% in the T8 temper. In another
embodiment, a new
2xxx aluminum alloy has a thickness of at least 12.7 mm and realizes an
elongation (ST) of at least
4.0% in the T8 temper. In yet another embodiment, a new 2xxx aluminum alloy
has a thickness
of at least 12.7 mm and realizes an elongation (ST) of at least 5.0% in the T8
temper. In another
embodiment, a new 2xxx aluminum alloy has a thickness of at least 12.7 mm and
realizes an
elongation (ST) of at least 6.0% in the T8 temper. In yet another embodiment,
a new 2xxx
aluminum alloy has a thickness of at least 12.7 mm and realizes an elongation
(ST) of at least 7.0%
in the T8 temper. The above elongation properties may be realized in products
having a thickness
22
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
of at least 25 mm, or at least 38 mm, or at least 50 mm, or at least 76 mm, or
at least 108 mm, or
higher. The above elongation properties may be realized in thin wrought
products having a
thickness of 7.0 to 12.6 mm.
[0056] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and is LT stress corrosion cracking resistant (defined below) in the T8
temper. The LT stress
corrosion cracking resistance properties may be realized in products having a
thickness of at least
25 mm, or at least 38 mm, or at least 50 mm, or at least 76 mm, or at least
108 mm, or higher. The
LT stress corrosion cracking resistance properties may be realized in thin
wrought products having
a thickness of 0.5 to 12.6 mm.
[0057] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and is ST stress corrosion cracking resistant (defined below) in the T8
temper. The ST stress
corrosion cracking resistance properties may be realized in products having a
thickness of at least
25 mm, or at least 38 mm, or at least 50 mm, or at least 76 mm, or at least
108 mm, or higher. The
ST stress corrosion cracking resistance properties may be realized in thin
wrought products having
a thickness of 7.0 to 12.6 mm.
[0058] In one embodiment, a new 2xxx aluminum alloy has a thickness
of at least 12.7 mm
and is both LT stress corrosion cracking resistant and ST stress corrosion
cracking resistant in the
T8 temper.
[0059] While the above properties generally relate to thick plate
products, similar properties
may also be realized in thick forged product and thick extruded products.
Further, many of the
above properties may be realized in combination, as shown by the below
examples.
v. Definitions
[0060] Unless otherwise indicated, the following definitions apply
to the present application:
[0061] "2xxx aluminum alloys" are aluminum alloys compositions
having copper as the major
alloying element as per the Aluminum Association definition provided in
"International Alloy
Designations and Chemical Composition Limits for Wrought Aluminum and Wrought
Aluminum
Alloys," a.k.a. the "Teal Sheets" (2015). For purposes of this patent
application, 2xxx aluminum
alloy compositions may be used in non-wrought products, such as in shape
castings, ingot/billet,
and additively manufactured products, among others. The 2xxx aluminum alloys
of the present
23
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
patent application are generally lithium-free, having less than 0.05 wt. % Li,
and generally less
than 0.03 wt. % Li, or less than 0.01 wt. % Li.
[0062] "Wrought aluminum alloy product" means an aluminum alloy
product that is hot
worked after casting, and includes rolled products (sheet or plate), forged
products, and extruded
products.
[0063] "Forged aluminum alloy product" means a wrought aluminum
alloy product that is
either die forged or hand forged.
[0064] "Solution heat treating" means exposure of an aluminum alloy
to elevated temperature
for the purpose of placing solute(s) into solid solution.
[0065] "Hot working" such as by hot rolling means working the
aluminum alloy product at
elevated temperature. Strain-hardening is restricted / avoided during hot
working, which generally
differentiates hot working from cold working.
[0066] "Cold working" such as by cold rolling means working the
aluminum alloy product at
temperatures that are not considered hot working temperatures.
[0067] Temper definitions are per ANSI H35.1 (2009), entitled
"American National Standard
Alloy and Temper Designation Systems for Aluminum," published by The Aluminum
Association.
[0068] Strength and elongation are measured in accordance with ASTM
E8/E8M-16ael and
B557-15. Plane-strain fracture toughness is determine in accordance with ASTM
339-20.
[0069] "LT Stress corrosion cracking resistant" means that at least
two-out-of-three specimens
of a 2xxx aluminum alloy product do not fail after 60 days of alternate
immersion testing at a net
stress of 300 MPa in the LT direction and in accordance with ASTM G47 using
constant-strain
type stressing frame fixtures according to Figure 4 of ASTM G49, and with
three replicate
specimens being required for testing. In one embodiment, all three specimens
do not fail after 60
days of alternate immersion testing at a net stress of 300 MPa in the LT
direction and in accordance
with ASTM G47. In another embodiment, all three specimens do not fail after 90
days of alternate
immersion testing at a net stress of 300 MPa in the LT direction and in
accordance with ASTM
G47. In one embodiment, all three specimens do not fail after 60 days of
alternate immersion
testing at a net stress of 350 MPa in the LT direction and in accordance with
ASTM G47. In
24
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
another embodiment, all three specimens do not fail after 90 days of alternate
immersion testing
at a net stress of 350 MPa in the LT direction and in accordance with ASTM
G47.
[0070] "ST Stress corrosion cracking resistant" means that at least
two-out-of-three specimens
of a 2xxx aluminum alloy product do not fail after 60 days of alternate
immersion testing at a net
stress of 250 MPa in the ST direction and in accordance with ASTM G47 and
using fixtures
according to G49, and with at least 3 specimens being required for testing. In
one embodiment,
all three specimens do not fail after 60 days of alternate immersion testing
at a net stress of 250
MPa in the ST direction and in accordance with ASTM G47. In another
embodiment, all three
specimens do not fail after 90 days of alternate immersion testing at a net
stress of 250 MPa in the
ST direction and in accordance with ASTM G47. In one embodiment, all three
specimens do not
fail after 60 days of alternate immersion testing at a net stress of 300 MPa
in the ST direction and
in accordance with ASTM G47. In another embodiment, all three specimens do not
fail after 90
days of alternate immersion testing at a net stress of 300 MPa in the ST
direction and in accordance
with ASTM G47.
vi. Miscellaneous
[0071] These and other aspects, advantages, and novel features of
this new technology are set
forth in part in the description that follows and will become apparent to
those skilled in the art
upon examination of the following description and figures, or may be learned
by practicing one or
more embodiments of the technology provided for by the present disclosure.
[0072] Among those benefits and improvements that have been
disclosed, other objects and
advantages of this invention will become apparent from the following
description taken in
conjunction with the accompanying figures. Detailed embodiments of the present
invention are
disclosed herein; however, it is to be understood that the disclosed
embodiments are merely
illustrative of the invention that may be embodied in various forms. In
addition, each of the
examples given in connection with the various embodiments of the invention is
intended to be
illustrative, and not restrictive.
[0073] Throughout the specification and claims, the following terms
take the meanings
explicitly associated herein, unless the context clearly dictates otherwise.
The phrases "in one
embodiment" and "in some embodiments" as used herein do not necessarily refer
to the same
embodiment(s), though they may Furthermore, the phrases "in another
embodiment" and "in
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
some other embodiments" as used herein do not necessarily refer to a different
embodiment,
although they may. Thus, various embodiments of the invention may be readily
combined, without
departing from the scope or spirit of the invention.
[0074] In addition, as used herein, the term "or" is an inclusive
"or" operator, and is equivalent
to the term "and/or," unless the context clearly dictates otherwise. The term
"based on" is not
exclusive and allows for being based on additional factors not described,
unless the context clearly
dictates otherwise. In addition, throughout the specification, the meaning of
"a," "an," and "the"
include plural references, unless the context clearly dictates otherwise. The
meaning of "in"
includes "in" and "on", unless the context clearly dictates otherwise.
[0075] While a number of embodiments of the present invention have
been described, it is
understood that these embodiments are illustrative only, and not restrictive,
and that many
modifications may become apparent to those of ordinary skill in the art.
Further still, unless the
context clearly requires otherwise, the various steps may be carried out in
any desired order, and
any applicable steps may be added and/or eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0076] FIG. 1 is a graph illustrating TYS(L) versus Kic(L-T) for
the Example 1 alloys.
[0077] FIG. 2 is a graph illustrating TYS(LT) versus Kic(T-L) for
the Example 1 alloys.
[0078] FIG. 3 is a graph illustrating TYS(ST) versus Kic(S-L) for
the Example 1 alloys.
DETAILED DESCRIPTION
Example 1
[0079] Several industrial scale DC ingots (18-inch x 80-inch) of
the 2xxx aluminum alloy
shown in Table 1 were homogenized and then conventionally scalped / peeled.
Table 1 - Composition of Ex. 1 Alloy (in wt. %)*
Si Fe Cu Mn Mg Zn Ti Zr Ag
0.02 0.05 4.9 0.35 0.4 0.5 0.11 0.07
0.35
* Nominal composition; the balance of the alloy was incidental elements and
impurities,
where the alloy contained not greater than 0.03 wt. % of any one impurity, and
where the
alloy contained not greater than 0.10 wt. %, in total, of all impurities.
26
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
The ingots were then hot rolled to a final gauge of 4.9 inches (124.5 mm) and
then cooled to room
temperature. The 2xxx aluminum alloy was then solution heat treated at 975 F
(523 C), water
quenched and then naturally aged for 10 hours. The final gauge materials were
then either
stretched either 2% or 8% and then artificially aged as shown in Table 2,
below.
Table 2 ¨Stretch and Artificial Aging Practices of the Ex. 1 Alloys
Stretch
Alloy (%) Aging Practice
Single step age:
la 2 = 16 hours at 350 F (176.7 C)
Single step age:
lb 2 = 24 hours at 350 F (176.7 C)
Single step age:
lc 2 = 36 hours at 350 F (176.7 C)
Single step age:
3a 8 = 16 hours at 350 F (176.7 C)
Single step age:
3b 8 = 24 hours at 350 F (176.7 C)
Single step age:
3c 8 = 36 hours at 350 F (176.7 C)
Multi-step aging:
2 2 = 24 hours at 350 F (176.7 C);
= Air cool to room temperature;
4 8 = Reheat - 24 hours at 270 F
The mechanical properties of the alloys were then tested. Strength and
elongation were determined
in accordance with ASTM E8/E8M-16ae1 and B557-15. Plane-strain fracture
toughness (Kic) was
determined in accordance with ASTM E399-20. The test results are shown in
Table 3, below and
are also shown in FIGS. 1-3.
Table 3 ¨ Mechanical Properties of Ex. 1 Alloys
Test Test TYS UTS Elong.
Alloy
Loc. Dir. (MPa) (MPa) (%) (MPn\ltn) orient.
la T/4 L 430 472 8.1 47.5
L-T
lb T/4 L 424 469 8.1 47.9
L-T
c T/4 L 414 463 7.8 48.3
L-T
2 T/4 L 428 474 8.1 46.5
L-T
la T/4 LT 427 480 7.4 46
T-L
lb T/4 LT 419 476 7.2 47.1
T-L
lc T/4 LT 412 471 7.1 45.8
T-L
2 T/4 LT 426 481 7.2 44.3
T-L
27
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
la T/2 ST 399 447 5.5 49.1 S-L
lb T/2 ST 393 447 5.2 47.8 S-L
lc T/2 ST 385 440 5.3 49.4 S-L
2 T/2 ST 396 447 5.3 48.1 S-L
3a T/4 L 441 477 9.5 45.6 L-T
3b T/4 L 432 473 8.4 46.3 L-T
3c T/4 L 423 467 8.1 44.6 L-T
4 T/4 L 436 476 8.2 43.2 L-T
3a T/4 LT 438 487 7.6 40.4 T-L
3b T/4 LT 430 481 7 41.1 T-L
3c T/4 LT 420 477 6,6 41.8 T-L
4 T/4 LT 434 484 6.8 42.1 T-L
3a T/2 ST 402 458 5.9 39.4 S-L
3b T/2 ST 400 456 5.5 41.9 S-L
3c T/2 ST 389 447 6 39.9 S-L
4 T/2 ST 396 455 5.5 40.1 S-L
[0080] As shown in FIG. 2, the multistep practice demonstrates
higher yield strength than the
350 F/24h aged condition. Also, the difference in properties is lower between
the 2% and 8%-
stretch for both strength and toughness, indicating the two-step aged
materials may be suited for
hydroforming applications (e.g., where a single hydroformed component may
contain regions of
variable strain and therefore variation in properties as a function of
location within the plate).
[0081] The SCC (stress corrosion cracking) properties of the alloys
in the ST direction were
also measured as per the "ST Stress corrosion cracking resistance" definition
provided above. The
SCC results are shown in Table 4, below. The specimen type was T-bar and the
location was T/2
for all tests.
Table 4 ¨ ASTM G44 SCC test results for Ex. 1 Alloys (ST direction)
Altern. Immer. ASTM G44
Stress
Alloy
(MPa) .Days Days to failure
in test rep 1 rep 2 rep 3
210 90 20 76 14
3a
250 90 4 14 90
l 210 90 0K90 31 0K90
a
250 90 0K90 40 0K90
3b 210 90 0K90 32 90
250 90 0K90 40 40
28
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
lb 210 90 0K90 90 0K90
250 90 0K90 0K90 76
210 90 0K90 40 0K90
3c
250 90 0K90 47 0K90
lc 210 90 01(90 0K90 01(9090
250 90 0K90 0K90 90
210 90 0K90 0K90 0K90
4
250 90 0K90 0K90 0K90
2 210 90 0K90 0K90 0K90
250 90 0K90 0K90 0K90
As shown, the multi-step aged alloys (both the 2% and 8% stretched materials)
did not realize any
failures over the 90-day test period at both the 210 MPa and the 250 MPa net-
stress levels.
Conversely, the single-step aged alloys realized multiple failures.
[0082] The SCC resistance of the alloys in the ST direction were
also tested at the seacoast to
test the alloys against corrosion in natural saltwater conditions. The
specimens for the seacoast
environment SCC testing are tested in constant strain fixtures (e.g., similar
to those use in
accelerated laboratory SCC testing). The seacoast SCC testing conditions
include continuously
exposing the samples via racks to a seacoast environment, where the samples
are ,=,' 1.5 meters from
the ground, the samples are oriented 45 from the horizontal, and a face of
the sample face the
prevailing winds. The samples are located 100 meters from the coastline. In
one embodiment, the
coastline is of a rocky nature, with the prevailing winds oriented toward the
samples so as to
provide an aggressive salt-mist exposure (e.g., a location similar to the
seacoast exposure station,
Pt Judith, Rhode Island, USA of Arconic Corp.). The test results are shown in
Table 5, below.
The specimen type was T-bar and the location was T/2 for all tests.
Table 5 ¨ Seacoast Testing SCC results for Ex. 1 Alloys (ST direction)
Point Judith, RI
Stress
Alloy (1V1Pa) Days in Days to
failure
test rep 1 rep 2 rep 3 rep 4
rep 5
210 201 T T T T T
lb 250 201 77 T T T T
300 201 59 82 T T T
210 201 T T T 192 T
3c 250 201 T T T 45 T
300 201 59 50 59 23
128
29
CA 03227929 2024- 2-2
WO 2023/028070
PCT/US2022/041247
210 201 T T T T T
4 250 201 T T T T T
300 201 T 192 T T T
210 201 T T T T T
250 201 T T T T T
2 300 201 T T T T T
250 201 T T T T T
300 201 T T T T T
= "T" = still in test
Again, the multi-step aged alloys (both the 2% and 8% stretched materials) did
not realize any
failures after 596 days in test at the 210 MPa and 250 MPa net-stress levels.
Conversely, the
single-step aged alloys realized multiple failures. At the 300 MPa net stress
level, only a single
specimen of the multi-step aged alloys failed (the specimen had 8% stretch) at
192 days of testing.
Conversely, at the 300 MPa net stress level, the single-step aged alloys
realized multiple failures,
most occurring in 60 days or less.
[0083] While various embodiments of the present disclosure have
been described in detail, it
is apparent that modifications and adaptations of those embodiments will occur
to those skilled in
the art. However, it is to be expressly understood that such modifications and
adaptations are
within the spirit and scope of the present disclosure.
CA 03227929 2024- 2-2
