Note: Descriptions are shown in the official language in which they were submitted.
CA 02763153 2014-09-18
BRAZING METHOD FOR JOINING USING AMORPHOUS SPUTTERED COATING
LAYER AS FILLER AND AMORPHOUS BRAZING FILLER FOR THE BRAZING
METHOD
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a brazing method for
joining using an amorphous sputtered coating layer as a
W filler, and an amorphous brazing filler for the brazing
method.
2. Description of the Related Art
Most structures, that is, a building, a transport
equipment, such as an automobile, a ship, an aircraft, a
train, and the like, all kinds of pipings, pipes, and the
like, have many equipment parts that need a joining between
metals or alloys, and high-temperature fusion welding way
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using Arc welding technique is mostly used for the joining
between metals and alloys. However, the fusion welding (or
welding) process has a limitation that mechanical properties
are deteriorated by changing the structures of the surrounding
base metals, such as a particle coarsening, a formation of
heat affected zone, and the like due to a high-temperature
operation, and also a material defect, such as a stress
corrosion cracking, and the like, is generated due to a
formation of internal stress by a high-temperature treating.
W In addition, there is a limitation that in the case of the
parts that need the joining of the thin-thickness or broad-
side as a shape, and a high-temperature structure, the
modification or erosion of base metal may be occurred so that
it is difficult to apply with the high-temperature welding
process. The above aspects considered, currently, the studies
about low-temperature solid-state welding technique using non-
fusion way are now actively proceeding, in which for the non-
fusion way, the base metal is not molten, and the low-
temperature solid-state welding technique gives sufficient
tensile strength and adhesive strength between metals and
alloys of the structure parts, and an excellent prevention
property of leakage.
The studies for applying a brazing technique that is one
of the solid-state welding techniques to the joining of
dissimilar metals, ceramics, high-temperature special
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materials, and the like, are actively proceeding, in which the
dissimilar metals, the ceramics, the high-temperature special
materials, and the like is impossible to join each other using
the fusion joining technique. The studies for applying the
brazing technique for all sorts of the parts for the high-tech
core industry facilities are proceeding because the brazing
technique not changes the base metals, and has a preferable
effect on the aspect of heat stress of joint while it does not
effect to the mechanical properties. Especially, the solid-
state joining technique, such as, the brazing, is applied to a
nuclear fuel tube that is one of core parts of nuclear reactor
for a nuclear industry, in which the nuclear fuel tube has the
thickness of very thin, i.e., not more than 0.4 mm so that the
base metals of the nuclear fuel tube are modified and eroded
when using the high-temperature joining technique.
Korean Patent Application Publication No. 2008-7006740
relates to amoLphous iron-nickel containing brazing foil and
brazing method, and more specifically, to an iron-nickel
containing brazing foil and brazing method, in which the
amorphous soft brazing foil has the composition including 25 5
a 5 50 atom%; 25 < b < 50 atom%; 5 < c 5 15 atom%; 4 5 d 5 15
atom%; 4 5 e 5 15 atom%; 0 5 f 5 5 atom%; 0 < g 5 6 atom96; and
additional impurities, where 10 5 d+e+g 5 28 atom% and
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FeaNibCreSidBeM0fPg, a+b+c+d+e+f+g=100. An excellent brazed joint
can be prepared by using the brazing foil. However, there is
a limitation that when filler in a type of the brazing foil or
ribbon is used, a precise control of thickness is difficult so
that the non-uniformity of filler thickness is caused and then
the non-uniformity of joint may be caused after joining.
Korean Patent No. 10-0597310 relates to a manufacturing
method of an attachment with Zr-Be alloy layer and a fusion
brazing joining process of nuclear fuel rod for heavy-water
W reactor by using the attachment. An
object of the above
invention is to suppress a delaminating of depositing layer
and a beryllium steam that can be generated when brazing due
to not use of a pure beryllium as a filler metal like the
prior art when joining an attachment (support, loose spacing
body, button, and the like) on the surface of nuclear fuel rod
that consists a nuclear fuel bundle for the safety of workers
and the prevention of environment pollution, and also
additionally is to improve a production yield of nuclear fuel
rod by decreasing a production loss rate of attachment and
nuclear fuel rod to be wasted that are generated by detaching
the attachment after brazing. However, there is a limitation
that for the brazing process, the joining is proceeded at high
temperature, i.e., above 1050 00 so that the control of joint
thickness is difficult due to an erosion of base metals when
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joining the attachment and nuclear fuel rod tube with very
thin thickness of 0.4 mm. In addition, there is a limitation
that in the terms of the physical properties of the joint, a
undesired micro structure is formed due to the formation of
harmful state, such as an intermetallic compound so that the
physical properties, such as a corrosion, a strength, and the
like are deteriorated.
Recently, there is a rising interest on low-temperature
brazing technique using low-melting amorphous filler in the
case of zirconium, titanium ally, and the like, and also on
the inserting technique of amorphous filler when joining in
order to secure uniformity.
For this reason, the present inventors developed a method
for brazing a multi-component amorphous alloy having low-
temperature melting point, and filler for the method, and
confirmed that the present invention is an effective brazing
method to a precise thickness control and uniform surface
component.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a
brazing method for joining using an amorphous sputtered
coating layer as a filler.
Another object of the present invention is to provide an
amorphous brazing filler for the method.
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The present invention provides a brazing method for
joining using an amorphous sputtered coating layer as a
filler, the method including: forming an amorphous coating
layer through a sputter coating on a joining part between
joining base metals (Step 1); and heating the joining part of
Step 1 (Step 2).
In addition, the present invention provides an amorphous
brazing filler used for the joining method. The amorphous
brazing filler includes Zr-Ti-x-y or Zr-Ti-x-y-z where x, y,
W and z are respectively selected from the group consisting of
alloy atoms including Cu, Ni, Fe, Al, Sn, and Be,
respectively, and x, y, and z are not identical in order to
achieve the objects as mentioned above.
When the multi-component amorphous inserting alloy
according to the present invention is coated on the surface of
base metals using a sputtering method that is one of a
physical vapor depositions, there are effects such that the
multi-component target composition can be intactly maintained
on the coating layer of base metals; the uniformity of
inserting layer according to the positions, such as, the
precise thickness control and the uniform applying of base
metals surface can be secured; and also perfect interface
contact can be perfoLmed to secure the uniformity and
reproducibility of the joint part when joining. In addition,
the filler according to the present invention has effective on
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In accordance with one aspect of the present invention,
there is provided a brazing method for joining using an
amorphous sputtered coating layer as a filler, the brazing
method comprising: forming an amorphous coating layer through
a sputter coating on a joining part between base metals
(Step 1); and heating the joining part of Step 1 (Step 2),
wherein the each of said base metal is a zirconium alloy,
wherein the filler is Zra-Tib-Cuc-Nid containing alloy where a,
W b, c, and d mean mass% of Zr, Ti, Cu, and Ni, respectively,
and 30a70, 5b15, 8c_20, and 1(31d.-20.
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brazing at low temperature due to a narrow fusion part and
low-fusion temperature thereby minimizing the modification and
erosion thereof.
BREIF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and other
advantages of the present invention will be more clearly
understood from the following detailed description taken in
conjunction with the accompanying drawings, in which:
Fig. 1 is a mimetic diagram of brazing using amorphous
filler.
Fig. 2 is a graph showing XRD analysis result of Zr62-
Ti11-Cu13-Ni14 (Example 1) alloy that is a crystalline target
for a sputter coating.
Fig. 3 is a graph showing XRD analysis result of coating
layer showing an amorphous structure after a sputter coating
of Zr62-T111-Cu13-Ni14 (Example 1) alloy.
Fig. 4 is SEM photograph showing the surface of coating
layer after a sputter coating of Zr62-Ti11-Cu13-Ni14 (Example 1)
alloy.
Fig. 5 is an observation photo showing a cross-section of
coating layer using an optical microscope after a sputter
coating of Zr62-Ti11-Cu13-Ni3.4 (Example 1) alloy.
Fig. 6 is a graph showing the result after performing a
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heat analysis after a sputter coating of Zr62-Ti11-Cu13-Ni14
(Example I) alloy.
Fig. 7 is SEM photograph showing a micro structure of a
joint (Example 2) using Zr62-T111-Cu13-Ni14 alloy; and
Fig. 8 is SEM photograph showing a micro structure of a
joint (Example 3) using Zr72-Ti7-0u8-Fe13 alloy.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Features and advantages of the present invention will be
more clearly understood by the following detailed description
of the present preferred embodiments by reference to the
accompanying drawings. It is first noted that teLms or words
used herein should be construed as meanings or concepts
corresponding with the technical sprit of the present
invention, based on the principle that the inventor can
appropriately define the concepts of the terms to best
describe his own invention. Also, it
should be understood
that detailed descriptions of well-known functions and
structures related to the present invention will be omitted so
as not to unnecessarily obscure the important point of the
present invention.
Hereinafter, the present invention will be described in
detail.
The present invention provides a brazing method for
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joining using a sputter coating, the brazing method including:
(Step 1) forming an amorphous coating layer through a
sputter coating on a joining part between base metals; and
(Step 2) heating the joining part of Step 1.
Hereinafter, the present invention will be described
step-by-step in detail.
Step 1 according to the present invention is to form an
amorphous coating layer through a sputter coating on a joining
part between base metals. When
using the conventional
amorphous alloy as a filler, it was used in a type of powder
using a gas atomization or as a filler after a production
process in a type of amorphous ribbon or foil with a melt
spinning. However, there are limitations that in the case of
the foil or ribbon, a precise control of thickness is
difficult to cause a non-unifoimity of filler thickness; and
in the case of the powder, a precise control of particles
sizes and a unifoim applying of filler on the surface of base
metals are difficult when joining. On the other hand, there
are advantages that when coating on the surface of base metals
using a sputtering method that is one of physical vapor
depositions, a multi-component target composition can be
intactly maintained at the coating layer; the thickness can be
controlled; it can be applied on the surface of base metals;
and also the perfect contact can be maintained on the
interface so that the uniformity and reproducibility of the
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joint can be secured.
Additionally, there is an advantage
that a coating can be uniformly performed even on the parts
with a wide area or complicated shapes so that it can be used
for various parts as compared with ribbon-type or foil-type
filler.
For Step 1, the joining base metal is a zirconium alloy,
and in this situation, filler to be coated is preferably Zr-
Ti-x-y or Zr-Ti-x-y-z (here, x, y, and z are one selected from
the group consisting of alloy atoms including Cu, Ni, Fe, Al,
M Sn, and Be, respectively, but x, y, and z are not identical).
The zirconium alloy is zirconium to which an element, such as,
Sn, Fe, Cr, Ni, Cu, Nb, and the like, is added, and includes
Zircaloy-1, Zircaloy-2, Zircaloy-3, Zircaloy-4, Low tin
improved Zicaloy-4, Ozhennite, and the like. The zirconium
alloy is an alloy that has very improved corrosion resistance
and mechanical property as compared with a pure zirconium.
Since an alloy element is generally added in less than 2-3 %,
a neutron absorption cross-sectional area of alloy is only
very little increased in the degree of about 0.2 barn. The
zirconium alloy is used for a nuclear fuel clad tube, guide
tube, spacer grid, and the like of light-water reactor and
heavy-water reactor due to the above features, and mainly used
for a nuclear fuel clad tube, pressure tube, Calandria Tube,
and the like.
The zirconium alloy is preferably Zircaloy-4. The
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general composition of Zircaloy-4 that is one type of the
zirconium alloy includes 1.2-1.7 wt% of Sn, 0.18-0.24 wt% of
Fe, 0.07-0.13 wt% of Cr, and a zirconium residue. The
zirconium alloys that are developed for more improving a
corrosion resistance and a mechanical property at the same
time in cooling water under the conditions of high-temperature
and high-pressure are used for a nuclear fuel clad tube of
light-water reactor that is mainly used in the whole world
power reactors until quite recently. There are Zircaloy-2,
M Zircaloy-4, and Ozhennite that are used in the former Soviet
Union as a typical alloy. Among
those, Zircaloy-4 is
frequently used for Pressurized Water Reactor (PWR).
The filler is preferably Zra-Tib-Cuc-Nid containing alloy
(a, b, c, and d mean mass% of Zr, Ti, Cu, and Ni,
respectively, and 305a570, 55b515, 85c520, and 105d520), and
more preferably, has Zr62-Ti11-Cu13-Ni14 alloy composition, or
Zra-Tib-Cuc-Fed containing alloy (a, b, c, and d mean mass% of
Zr, Ti, Cu, and Fe, respectively, and 405a580, 55b515, 55c515,
and 55d515), and more preferably, has Zr72-Ti7-Cu8-Fe13 alloy
composition. Since the alloy has low melting point, it has an
effect in preventing erosion, a modification, and a mechanical
deterioration of base metals when heat-treating for brazing.
The thickness of the filler to be coated in Step 1 is
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preferably 5-200 gm. There
are limitations that when the
thickness of the filler is below 5 M, it is not sufficient
for a role as a joining material, and when the thickness of
the filler exceeds 200 M, an excessive amount of filler flows
out in a liquid phase when melting or a good joint structure
is difficult to form.
Step 2 according to the present invention to heat to a
joining part. With reference to the mimetic diagram as shown
in Fig. 1, the principle of the brazing according to the
W present invention is as follows. When
solid filler(B) is
added between the base metals(Al, A2), and then heated, the
filler is melted and then liquid filler and base metals are
diffused so that the joining between the filler and base
metals is done due to isothermal solidification diffusion.
Meanwhile, infrared heating equipment among heat transfer
equipments is known as very fast heat transfer equipment
because most atomic bonds of objects are easily excitated in
an infrared radiation area due to an electro-magnetic
radiation. Additionally, an infrared heating has an advantage
that it can heat only desired part by a direct radiation
thereto using a coldwall process. Accordingly, the infrared
heating with the above-explained advantages may be efficiently
used for the heating of Step 2, but not limited thereto.
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For Step 2, when the joining base metals is a zirconium
alloy and the filler to be coated is Zra-Tib-Cuc-Nid (a, b, c,
and d are mass% of Zr, Ti, Cu, and Ni, respectively, and
305a570, 55b15, 85.c20, and 10,0120), preferably the
maintenance temperature is 720 - 1050 C and the maintenance
period is 0.5 - 60 minutes. Since
the ranges of solidus
temperature and liquidus temperature of Zra-Tib-Cuc-Nid (a, b,
c, and d are mass% of Zr, Ti, Cu, and Ni, respectively, and
305a570, 85-c520,
and 105d520) alloy are 720 - 1050 C,
to there are limitations that when the maintenance temperature is
below 720 "ID, the filler is not melted so that the brazing is
not performed and when the maintenance temperature exceeds
1050 C, a fine structure modification or excessive erosion is
caused to the base metals.
Moreover, the maintenance
temperature is more preferably minimum at least 30 ct than the
melting temperature of filler when heating.
For Step 2, when the joining base metals is a zirconium
alloy and the filler to be coated is zra-Tib-Cuc-Fed (a, b, c,
and d are mass% of Zr, Ti, Cu, and Fe, respectively, and
405a80, 55c515, and
5c1.15), preferably the
maintenance temperature is 720 - 1050 cC and the maintenance
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period is 0.5 - 60 minutes. Since
the ranges of solidus
temperature and liquidus temperature of Zra-Tib-Cuc-Fed (a, b,
c, and d are mass% of Zr, Ti, Cu, and Fe, respectively, and
405a580, 551D15, 5c515, and 5ci-5_15) alloy are 720 - 1050 C,
there are limitations that when the maintenance temperature is
below 720 C, the filler is not melted so that the brazing is
not performed and when the maintenance temperature exceeds
1050 C, a fine structure modification or excessive erosion is
caused to the base metals.
Moreover, the maintenance
M temperature is more preferably minimum at least 30 C than the
melting temperature of filler when heating.
For Step 2, the heat treating is preferably performed
under an inert atmosphere, such as, for example an argon
atmosphere. There is an effect on preventing the production
of impurities of alloy in the joining material by blocking the
contact with oxygen during heat-treating.
The brazing method for joining according to the present
invention may be usefully applied to a nuclear fuel rod of
heavy-water reactor. For the brazing of nuclear fuel rod of
the conventional heavy-water reactor, a beryllium is deposited
and then heat is applied to join, but there was limitation
that a flaking phenomenon, in which a beryllium layer is
fallen out during the brazing process, is generated to cause
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the defect of the joint, in addition to a harmful problem of
beryllium. For another method, Zr-Be alloy was prepared to
use for brazing, but there was limitation that the operation
should be performed at high temperature of above 1050 'C and
the structural safety of the joint is not secured. Meanwhile,
for the brazing method for joining using the sputter coating
layer according to the present invention as a filler, there
are advantages that when coating on the surface of base metals
using the sputtering method that is one of physical vapor
W depositions, the multi-component target composition can be
intactly maintained on the coating layer of the surface of
base metals; the thickness can be easily controlled; it can be
uniformly applied to the surface of base metals; and also the
perfect contact can be maintained on the interface.
Therefore, the unifoLmity and reproducibility of the joint can
be secured.
Additionally, the present invention provides amorphous
brazing filler used for the method for joining, in which the
filler is Zr-Ti-x-y or Zr-Ti-x-y-z (here, x, y, and z are one
selected from the group consisting of alloy elements including
Cu, Ni, Fe, Al, Sn, and Be, respectively, but x, y, and z are
not identical). When the alloy elements, such as, Cu, Ni, Fe,
Al, Sn, and Be, are added to the zirconium alloy, the melting
point of the inserting alloy is decreased so that the
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temperature for joining can be decreased and also the joint
with the same corrosion resistance and mechanical property as
the zirconium alloy that is base metals can be secured by
maximizing the joint structure.
The brazing filler can be usefully applied to the
zirconium alloy joining. The zirconium that consists the
brazing filler has a thermal neutron absorption cross-section
of 0.18 barn that is smaller than 0.23 barn of aluminum as
well as about 3.2 barn of stainless steel. Moreover, it is
M very suitable to use as a reactor core material of a nuclear
reactor because it has excellent mechanical property and
corrosion resistance and also excellent compatability with
uranium dioxide (UO2) that is used as a nuclear fuel.
The filler preferably includes 30-70 wt% of Zr, 5-15 wt%
of Ti, 8-20 wt% of Cu, and 10-20 wt% of Ni, and the contents
of the filler are more preferably 62 wt% of Zr, 11 wt% of Ti,
11 wt% of Cu, and 14 wt% of Ni, respectively. The melting and
coagulation phenomenon are occurred in the very narrow range
of temperature for the brazing filler.
Specifically, the
ranges of liquidus temperature and solidus temperature of the
filler that is Zr30_70-Tis-15-Cue-20-Ni10-20 according to the present
invention are 720 - 950 C, and the solidus temperature is
770 00 and the liquidus temperature is 815 C in the case of
the brazing filler with Zr62-Ti11-Cu13-Ni14 alloy composition.
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Also, The filler preferably includes 40-80 wt% of Zr, 5-15 wt%
of Ti, 5-15 wt % of Cu, and 5-15 wt% of Fe, and the contents of
the filler are more preferably 72 wt% of Zr, 7 wt% of Ti, 8
wt% of Cu, and 13 wt% of Fe, respectively. The melting and
coagulation phenomenon are occurred in the very narrow range
of temperature for the brazing filler.
Specifically, the
ranges of liquidus temperature and solidus temperature of the
filler that is Zr40-80-Ti5_15-Cu5....15-Fe5_15 according to the present
invention are 720 - 1050 00, and the solidus temperature is
820 "ID and the liquidus temperature is 845 C in the case of
the brazing filler with Zr72-T17-Cu8-Fe13 alloy composition. As
mentioned above, there are advantages that the brazing filler
has a narrow melting temperature range, so that the
ununiformly melting of the filler is reduced thereby improving
a flow rate and the brazing filler has a low melting
temperature so that the structural modification and the
decrease of the mechanical property of base metals are not
caused, and also it is possible to join.
The brazing filler with Zr62-Ti11-Cu13-Ni14 alloy
composition according to the present invention has low melting
point as mentioned above, and it can be explained from the
fact of the eutectic reaction between the component phases
that consists the composition. When the content of nickel is
constant as 33.3 atom% for the alloy system consisting of Zr-
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Ti-Ni, the component phase of zirconium-rich area is consisted
of two phases of Zr2Ni and (Zr, Ti)2Ni phases and it is known
that there is Zr2Ni-(Zr, Ti)2Ni binary eutectic point of 850 'C
by the eutectic reaction between the component phases, and in
this situation, copper is added as a melting point depprassant
to obtain more low-melting point. That is,
Zr-Ti-Cu-Ni
quarternary alloy composition allows to more reducing the
solidus temperature and liquidus temperature by substituting a
part of nickel that is included in Zr-Ti-Ni ternary alloy
M composition with copper.
Therefore, there is an advantage
that the structural modification and deterioration damage of
base metals can be minimized by using the alloy composition as
mentioned above as the brazing filler.
A bulk target preparation should be performed in order to
use the brazing filler as mentioned above as a target of
sputtering. The
preparation of the bulk target may use a
powder metallurgy process, including preparing an alloy powder
using a casting process by vacuum arc melting or gas atomizing
and then bulking the alloy powder using some spark plasma
sintering. A casting
process allows giving a shape to a
molten metal using a cast and then coagulating to prepare a
crystalline structure.
Meanwhile, the powder metallurgy
process allows preparing a desired shape through the
processing, such as preparing a metal powder, then pressuring
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thereon, and the like, and then heating the desired shape at
the temperature of not more than melting point of the metals
therein to coagulate so that it is prepared as an amorphous
state. Generally, the amolphous metal is used as a target of
sputtering. However, there is an advantage that even though
the target is the crystalline structure in the case of the
filler according to the present invention, after sputtering it
changes to the amorphous state, so that the filler can be
prepared through the casting.
Hereinafter, the present invention will be described in
more detail. However, the following Examples are only for
illustrating the present invention, but the context is not
limited to the following Examples.
<Example 1> Preparation of Zr62-Tin-Cu13-Ni14 Alloy Target
Zr62-Ti11-Cu13-Ni14 alloy target was prepared by a casing
process of 62 wt% of Zr, 11 wt% of Ti, 13 wt% of Cu, and 14
wt% of Ni using a vacuum arc melting furnace.
<Example 2> Brazing Joining 1 Using Zru-Ti 11-Cul3-Nim
Filler
Step 1. Introducing Filler to Joining Part through
Sputter Coating
A sputter coating was performed using the alloy prepared
from Example 1 as a target after placing one side of Zircaloy-
4 alloy to be used as a base metal of joining to the sputter
apparatus. At this point, an initial high vacuum was set to
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be not more than 10-5 torr using a diffusion pump, a thin-film
deposition pressure was set to be 2 x 10-2 torr, and an argon
was supplied in 15 sccm to perform the coating for 120 minutes
thereby introducing the filler prepared from Example 1 to the
base metal of joining in a thickness of 70 F.
Step 2. Heating to Joining Part
A infrared brazing was performed by preparing Zircaloy-4
alloy base metal to be joined to the side that was coated with
the filler in Step 1. At this point, a rising temperature was
W 100 C/min., and a maintenance temperature was 790 C when
infrared heating. It was maintained at the above temperature
for 10 minutes, then cooled in 50 C /min. for heating, and
also was performed under the atmosphere of argon.
<Example 3> Brazing Joining 2 using Zr62-Tin-Cun-Ni
--14
Filler
A brazing joining was performed with a base metal of
joining by using the same process with Example 2, except that
the maintenance temperature of Step 2 was 850 ct in Example 2.
<Example 4> Brazing Joining 3 using Zr72-Ti7-Cu8-Fe13Filler
A brazing joining was performed with a base metal of
joining by using the same process with Example 2, except that
the maintenance temperature of Step 2 was 910 C in Example 2.
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<Experimenting Example 1> XRD Analysis of Zr62-Ti11-Cu13-
Ni14Filler Target
In order to confirm a crystalline property of the filler
target introduced to the sputter coating, the filler target
prepared from Example 1 was analyzed using XRD (X-ray
Diffraction) and then the results were shown in Fig. 2.
As shown in Fig. 2, it could be found that the target
prepared by the vacuum arc melting has the crystalline
W property, in which it crystals in various phases.
<Experimenting Example 2> XRD Analysis of Sputtered Zr62-
Ti11-Cu13-Ni14 Filler Coating Layer
In order to confilm the crystalline property of the
filler-coating layer after sputtering, the Zr62-Ti
_11-Cun-Nim
filler coating layer obtained by performing only Step I of
Example 2 was analyzed using XRD (X-ray Diffraction), and the
results were shown in Fig. 3.
As shown in Fig. 3, it could be found that the structure
of the filler alloy prepared from Example 1, in which the
filler alloy was presented as the crystalline alloy, became an
amorphous structure through sputtering. It means that even
though the structure of target was crystalline, it can form an
amorphous coating layer through sputtering.
<Experimenting Example 3> SEM Observation after Sputter
Coating of Zr62-Ti11-Cu13-Ni1.4 Filler
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In order to confilm a uniformity of surface after coating
of filler, a zirconium alloy specimen prepared by performing
only Step 1 of Example 2 was observed through SEM, and then
the results were shown in Fig. 4.
As shown in Fig. 4, it could be found that the filler was
uniformly coated on the surface of base metals.
<Experimenting Example 4> Observation of Cross Section
after Sputter Coating of Zru-Tin-Cun-NilAFiller
In order to confirm as to whether the filler coated has a
W unifoLm thickness, a cutting section of the sidepiece of the
zirconium alloy specimen prepared by performing only Step 1 of
Example 2 was observed using an optical microscope, and then
the results were shown in Fig. 5.
As shown in Fig. 5, it could be found that the coating
layer to the base metals was well coated with a uniform
thickness and it formed a perfect interface.
<Experimenting Example 5> Heat Analysis after Sputter
Coating of Zr62-Ti11-Cu13-Ni14 Filler
In order to confiLm a liquidus temperature and solidus
temperature of filler after sputter coating, the alloy
prepared from Example 1 was sputter-coated on a vanadium thin-
film under the same condition as disclosed in Step 1 of
Example 2; then was heat-analyzed using DTA (Differential
Thermal Analyzer); and then the results were shown in Fig. 6.
According to Fig. 6, a lateral axis indicates a
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CA 02763153 2015-07-16
In order to analysis a micro structure after brazing of
filler joined from Example 3, it was observed using SEM and
then the results were shown in Fig. 7.
Both sides of the joint were the structure of joining
base metal. As shown in Fig. 7, it could be found that the
brazing joining was properly performed because the joint has
Zr containing solid solution phase that has not fragile
intermetallic compounds due to the sufficient isothermal
solidification diffusion between the filler and base metals.
<Experimenting Example 7> Observation of Micro structure
after Brazing of Zr72-Ti7-Cu8-Fe13 Filler
In order to analysis a micro structure after brazing of
filler joined from Example 4, it was observed using SEM and
then the results were shown in Fig. 8.
Both sides of the joint were the structure of joining
base metal. As shown in Fig. 8, it could be found that the
brazing joining was properly performed because the joint has
Zr containing solid solution phase that has not fragile
inteLmetallic compounds due to the sufficient isothermal
solidification diffusion between the filler and base metals.
Although the preferred embodiments of the present
invention have been disclosed for illustrative purposes, those
skilled in the art will appreciate that various modifications,
additions and substitutions, are possible.
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CA 02763153 2014-09-18
The scope of the claims should not be limited by the
preferred embodiments set forth in the examples, but should be
given the broadest interpretation consistent with the
description as a whole.
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