Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02425118 2009-01-07
1
LEAD FREE POVVDERED METAL PROJECTILES
CROSS-REFERENCE TO RELATED APPLiCATION
This is a Continuation-in-Part of copending U.S. Patent 6,691,623, which is a
Continuation of U.S. Patent 5,917,143.
BACK+OROtJhjD =QF..THE.RNM.MQN
This invention relates. to lead free projectiles,. Spcxifioally, _this
invantion rela:tes to
lead free pro3ectiles that are signiftcaatiy less:dgc" lm.Fr4wious
1e.ad.containing ._
projectiles. More spocifwally; tlusiaveatiou,,relates to lead fi:eaprojectiles
tliat:are
designed :to
significantly less dense than pa~eviQU&: lead A-m prujoctiles, which were
approxiaiate.the :theorelical dwsi#y: of l~, . :
Because lead is a potential.source of environmental problems and health
concerns,
there-is a need for Jead;f= proj.ectile,s and amrnwu~ion, as we19 as a met&od
of
manuActuri~such lead fm.prgje¾tiles.a.nd.amm~tion: Frangible.lead
fieeprojectiles
are.useftil iq}ndoorshootinsg,ra~ges,:aad;~duce aay gotentiai:,problenns
nesulting from
airborne, lead dust, a.s: w.e~ as; rpd citig vosgy envimnmemtal clowup. Non
fraagibie lead
f(ee projectiles; uleM. in hupting ap.d other: outdoor. activiti,es,
especially when such
actxvities, ooan' tu eav, omentail-Y sqnsitive aceas.
Previous lead &ee projectiles were conceived, design4.configured and
manufactured to simulate, as aecurately as possible, the theoretieal c~&sity
iof lead. Such
simulation was previously thought to be desimble so t#Lt a shoQter would not
perceive a
great difference between the feel of shooting a projectile containing.lead and
one that is
lead free. . For- eaample, in U.S.Patent 5,760,33.1,. Lowden .eta1.. disclose
a lead free
praojectile designed to closely. approximate the density of lead.by-
incorpdrating a denser
tham lead component and a less dense than lead component
One solation to the need for lead free projectiles has been the use of a
c.ompacted,
unsintered admixture of.metal particles comprising tungsten and at least.one
other metal
selected from4he group of iron and copper. However, the admixture process and
the use
of tungsten adds to the cost ofmanufacturing sucli projectiles.
CA 02425118 2009-01-07
2
SUMMARY OF THE INVENTION
The present invention provides lead free projectiles that are not limited by
the
theoretical density of lead, and thus offers more flexibility in terms of
materials used and
methods of manufacture. The projectiles of the present invention satisfy the
need for lead free
projectiles without the expense of high cost materials and processing. The
projectiles of the
present invention produce a similar "feel" and mimic the ballistic properties
of lead projectiles
of similar caliber and size, as well as similar lead free projectiles.
Specifically, the present
invention provides an alternative to lead that is less dense than lead but
still retains similar
external ballistic properties. In preferred embodiments, the projectiles of
the present invention
exhibit external ballistic properties similar to previous lead containing and
lead free
projectiles, especially when fired within ranges of about 100 yards or less.
Specifically, the present invention provides a lead free projectile comprising
a
compacted admixture of a high ductility metal powder and a. low ductility
metal powder,
wherein the low ductility metal powder is less dense than lead and the
projectile is less dense
than lead. Alternatively, the present invention provides a lead free
projectile having a density
less than the theoretical density of lead. The present invention also provides
a lead free
projectile comprising a compacted admixture of iron powder and at least one
powder selected
from tin, zinc and alloys and mixtures thereof.
In accordance with an aspect of the present invention, there is provided a
lead free
projectile comprising a compacted admixture of iron powder and at least one
powder selected
from tin, zinc and alloys and mixtures thereof.
In accordance with another aspect of the present invention, there is provided
a lead
free projectile comprising a compacted admixture of at least one high
ductility metal powder
and a low ductility metal powder, wherein the projectile has a density of less
than about 80%
of the theoretical density of lead.
In accordance with another aspect of the present invention, there is provided
a lead
free composite projectile comprising a compacted admixture of a high ductility
metal powder
and a low ductility metal powder, wherein the low ductility metal powder is
less dense than
lead and the projectile is less dense than lead.
In accordance with another aspect of the present invention, there is provided
a lead
free projectile comprising a compacted admixture of a high ductility metal
powder and a low
CA 02425118 2009-01-07
2a
ductility metal powder, wherein the high and low ductility powders are within
a density ration
or range of about 0.260 - 0.280 Ibm/cubic inch.
In accordance with another aspect of the present invention, there is provided
a lead
free projectile comprising a compacted admixture of a high ductility metal
powder and a low
ductility metal powder, wherein the high and low ductility powders are within
a density ration
or range of about +/- 10% of the apparent density of iron powder.
In accordance with another aspect of the present invention, there is provided
a lead
free projectile having a density less than the theoretical density of lead.
In accordance with another aspect of the present invention, there is provided
a lead
free projectile comprising a compacted admixture of about one part by volume
iron powder
and about two parts by volume of at least one powder selected from tin, zinc
and alloys and
mixtures thereof, and wherein the compacted admixture has a density less than
70% of the
theoretical density of lead.
DETAILED DESCRIPTION OF THE INVENTION
The projectiles of the present invention, and the processes for manufacturing
them,
will be more fully understood by reference to the following description. When
used herein,
projectile includes bullet, shot, and other projectiles associated with
firearms. Projectile as
used herein include core, which is formed from the compacted metal powders, as
well as the
jacketed or unjacketed core that can be loaded into a cartridge to form a
round of ammunition.
Variations and modifications of both the projectiles and the processes can be
substituted
without departing from the principles of the invention, as will be evident to
those skilled in
the art.
The projectiles of the present invention comprise a mixture of metal powders,
and can
comprise lubricants and other materials that aid in the manufacture of such
projectiles.
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
3
The metal powder is a mixture of at least one high ductility metal powder and
at least one
low ductility metal powder. The high ductility metal powder facilitates cold
forming and
ease of manufacture of the powder metal mixture into a finished projectile
shape by
conventional projectile forming technology. The low ductility metal powder
reduces the
overall cost of the powder metal mixture by acting as a filler that does not
sacrifice the
material properties of the low ductility metal.
The high ductility metal powder can be a single metal or a mixture of metal
powders having high ductility. High ductility as used herein means that the
stress-strain
characteristic of the material will have an almost indistinguishable
transition between
elastic and inelastic response regions. Examples of high ductility metal
powders that can
be used according to the present invention include tin, zinc, copper,
aluminum, brass, and
to a lesser extent gold and platinum. To the extent that any material used is
more dense
than lead, the low ductility rrietal should be less dense than lead. Of the
above high
ductility metals that can be used, tin and zinc are.particularly preferred.
The selection of a
particular high ductility metal powder or mixture of powders will depend on a
variety of
factors, including the particular low ductility metal material used, and the
ratio of low
ductility to high ductility metal powder used in fabricating the projectile.
In addition,
where the high ductility metal powder comprises a mixture of metal powders,
metals with
lower ductility may be used in combination with the preferred high ductility
metals to
form a compact having high ductility.
The density of the high ductility metal powder is preferably less than the
theoretical density of lead, however, the density of the high ductility metal
powder can be
greater than lead if the density of the projectile is less than lead. In
addition, if the high
ductility metal powder consists of a mixture of powders, the mixture can
contain metals of
varying density. Again, it is preferred that the density of such mixtures be
less than the
theoretical density of lead, but the density of the mixture can be greater
than lead so long
as the composite density of the projectile is less than the theoretical
density of lead.
The low ductility metal powder can be a.single metal,or a mixture of metal
powders having low ductility. Low ductility as used herein means that the
material will
have a well defined transition between elastic and inelastic response regions
in the stress-
strain characteristic relationship of the material. Examples of low ductility
metal powders
that can be used according to the present invention include iron, steel,
stainless steel and
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
4
nickel. Of these, iron is particularly preferred. The selection of a
particular low ductility
metal powder or mixture of powders will depend on a variety of factors,
including the
particular high ductility metal material used, and the ratio of low ductility
to high ductility
metal powder used in fabricating the projectile. In addition, where the low
ductility me,tal
powder comprises a mixture of metal powders, metals with higher ductility can
be used in
combination with the preferred low ductility metals to form a mixture having
low ductility.
The density of the low ductility metal powder is preferably less than the
theoretical
density of lead, however, the density of the low ductility metal powder can be
greater than
lead if the composite density of the projectile is less than lead. In
addition, if the low
ductility rnetal powder consists of a mixture of powders, the mixture can
contain metals of
varying density. Again, it is preferred that the density of such mixtures be
less than the =
theoretical density of lead, but the density of the mixture can be greater
than lead so long
as the density of the projectile is less than lead.
Regardless of the densities of each of the high and low ductility metal
powders, the
density of the projectile formed from the powders is preferably less than the
theoretical
density of lead.
To obtain a projectile of the present invention, it is preferred that the
projectile
comprise about two parts by volume of high ductility metal powder to one part
low
ductility metal powder. The preferred ratio ensures that the compacted metal
powder
mixture will take on properties, including properties such as ductility and
formability that
aid in the production of projectiles of the present invention, of the powder
metal more
highly represented in the mixture. The preferred material properties are those
of the higher
ductility metal powder, and thus it is preferred that the higher ductility
metal powder
comprise a higher percentage of the mixture.
The projectiles of the present invention can be manufactured by a wide variety
of
methods. Typically, the projectiles are made by coinpacting the mixture of
metal powders,
.and then finishing the projectile, if necessary, by sintering, swaging, or
otherwise
modifying the compacted mixture. Other finishing steps can include jacketing
the
compacted mixture. Jacketing can be accomplished by a wide variety of known
methods.
Compacting can be carried out at substantially ambient conditions, without
applied heat, or
under heated conditions. The method of manufacture will vary depending on a
wide
variety of parameters, including the desired projectile, the specific
composition of the
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
metal powders, the particle size of the metal powders, and other factors that
will be
obvious to one skilled in the art.
When compacting a mixture of metal powders, it is preferred that the low
ductility
powder have a pre-compaction particle size distribution of about from 44 to
250 m. More
5 specifically, a preferred low ductility mixture can have a particle
distribution of about 15
to 25% by weight of particles up to about 44 m, about from 5 to 70% by weight
of
particles having a particle size of about from 44 to 149 m, and about from 5
to 15% by
weight of particles having a particle size of about from 149 to 250 m. Even
more
advantageous is a pre-compaction particle size distribution of about 22% by
weight of
particles up to about 44 m, about 68% by weight of particles having a
particle size of
about from 44 to 149 m, and about 10% by weight of particlea having a
particle size of
about from 149 to 250 gm. The desired particle size distribution can be
determined and
obtained through a variety of conventional methods, including optical
measurements and
sifting. The particles are also available commercially in specific particle
size distributions.
A preferred high ductility material comprises powder having a pre-compaction
particle
size distribution of about from 45 to 180 m. More specifically, a preferred
high ductility
mixture can have a particle distribution of about 10-14% by weight of
particles up to about
45 m, about from 30-50% by weight of particles having a particle size of
about 75 m,
about from 20-30% by weight of particles having a particle size of about 106
m, about
from 5-10% by weight of particles having a particle size of about 150 m, and
about from
2-4% by weight of particles having a particle size of about 180 m. Even more
advantageous is a'pre-compaction particle size distribution for the low
ductility metal of
about 14% by weight of particles of about 45 m, about 48% by weight of
particles having
a particle size of about 75 m, about 28% by weight of particles having a
particle size of
about 105 m, about 7% by weight of particles having a particle size of about
150 in, and
about 3% by weight of particles having a particle size of about 180 m.
Some embodiments of the projectile of the present invention may be frangible.
Frangible as used herein, consistent with its use in the firearms and
ammunition industry,
means that the projectile breaks apart completely upon striking a hard target.
Frangible
lead free projectiles of the present invention can be prepared by a process of
manufacture
involving only the cold compacting of the high and low ductility metal
powders. Non
frangible projectiles can be made by cold compacting the metal powders, and
can also be
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
6
made by heat treating the cold compacted metal powders to strengthen the bond
between
the powders. Frangibility depends, at least in part, on the particle size
distribution of the
high and low ductility metals used. It has been found to be particularly
advantageous to
have a pre-compaction particle size distribution of about from 15 to 25% by
weight of
particles up to about 44 m, about from 5 to 70% by weight of particles having
a particle
size of about from 44 to 149 m, and about from 5 to 15% by weight of
particles having a
particle size of about from 149 to 250 in. Even rriore advantageous is a pre-
compaction
particle size distribution of about 22% by weight of particles up to about 44
m, about
68% by weight of particles having a particle size of about from 44 to 149 m,
and about
10% by weight of particles having a particle size of about from 149 to 250 m.
The
desired particle size distribution can be obtained through a variety of
conventional =
methods, including optical measurements and sifting. The particles are also
available
commercially in specific particle size distributioris.
Many other particle sizes and particle size distributions can be used to
fabricate a
projectile of the present invention, including non frangible projectiles.
Typically, the
particle size of each of the powders can vary, depending 'on a variety of
factors such as the
ratio of metal powders, and the ratio of the particle sizes of the metal
powders. In addition
to the wide variety of particle sizes that can be used, it is preferred that
the particles be of
irregular shape to promote bonding and strength. It has been found that
irregularly shaped
particles, when used according to the present invention and when used as
components in
projectiles of the present invention, improve the bonding of the metal powders
and
contribute to the green strength of the compacted projectiles, as compared to
spherical or
regularly shaped particles.
The particle size distributions described above have been found to provide the
advantage of integrity of the projectile before and during firing and
frangibility upon
impact with a target media. While the relationship'between particle size
distribution and
frangibility are not fully understood, it is believed to be a function of the
mechanical
interlocking of the particles after the cold compaction of the high and low
ductility metal
powders. In addition, the preferred particle size distribution has been.found
to provide
strength to the compacted coinposite projectiles of the present invention, and
is thought to
be one factor enabling the formation of unsintered projectiles of the present
invention. By
providing such increased robustness and strength, the preferred particle size
distribution
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
7
may provide one factor allowing simplified fabrication of the projectiles of
the present
invention, involving merely the cold compacting of the metal powders.
The projectiles of the present invention can be manufactured by a process
wherein
the high and low ductility metal powders of the desired particle sizes are
admixed to
provide a mixture with the desired ratio of metal powders and if desired, with
a desired
particle size distribution. The high and low ductility metal powders can also
preferably be
mixed with one or more lubricants or a inixture of lubricants. A lubricant
aids in
removing the projectiles from the mold after compaction is complete. If a
lubricant is to
be added, it can be added to either metal powder or the mixture of metal
powders. A
preferred lubricant is zinc stearate, which can be used alone or in
combination with other
lubricants. Up to about 1.0% by weight of zinc stearate can be beneficially
added to the
mixture of high and low ductility metal powders prior to compaction. ., About
0.5% has
been found to be particularly satisfactory.
The admixture is then placed in a die which is designed to provide the desired
shape of the projectile. A wide variety of projectiles can be made according
to the present
invention, including shot and bullets. The invention is particularly
beneficial in bullet
manufacture, and especially those having a generally elongated configuration
in which a
leading end has a smaller circumference than a trailing end.
For both frangible and non frangible projectiles according to the present
invention,
the mixture of high and low ductility metal powders is cold compacted at a
pressure of
about from 50,000 to 120,000 psi, with a pressure of about 100,000 psi being
particularly
preferred. Compacting at a pressure of about 100,000 psi provides the optimal
combination of projectile integrity before and during firing and frangibility
upon impact
with a target. The compaction step can be performed on any mechanical press
capable of
providing at least about 50,000 psi pressure for a dwell time which can be
infinitesimally
small. Presently available machinery operates with dwell times of about from
0.05 to 1.5
seconds. Preferably, a conventional rotary dial press is used. A compaction
ratio of about
1.8 to 2.3 is preferred. Compaction ratio is used herein in the common sense,
meaning that
the initial volume of power is compared to the volume of the compacted
composite that
can form a projectile of the present-invention. For non-frangible projectiles,
the process
may be varied in tenns of compaction time or pressure, or the process could
further
comprise heat treatment such as sintering.
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
8
After the projectile is formed by cold compaction, a jacket can be formed
around
the projectile if so desired. Some embodiments of the projectiles of the
present invention
do not require jackets. The need to incorporate a jacket into the projectiles
of the present
-invention will depend upon the specific mixture and composition of the metal
powders
used to fabricate the projectile. In other embodiments, a jacket may be
preferred for a
variety of reasons. For example, the jacket can isolate the powdered iron
material of the
projectile from a gun barrel, preventing erosion of the rifling of the gun
barrel which might
result from direct contact between the interior surface of the barrel and the
powdered iron
of the projectile. The jacket also helps provide additional integrity of the
projectile before
and during firing as well as improving the ballistics of the projectile upon
firing. The
jacket material can be selected from those customarily used in the art, for
example, metal
or polymeric material. Metals which can be used include aluminum, copper, zinc
and
combinations thereof, with copper or brass being a preferred choice. Polymeric
materials
which can be used include polyethylene and polycarbonate, with a low density
polyethylene material being preferred.
In the case of metal jackets, the jacket can be applied by any number of
'conventional processes, including acid or cyanide electroplating, mechanical
swaging,
spray coating, and chemical adhesives. The preferred method is electroplating.
A variety of electroplating techniques can be used in the instant invention,
as will
be evident to those in the plating art. In general, the projectiles are
cleaned and sealed
b,efore the final plating. The sealing can be with impregnating methacrylate
and polyester
solutions.
In a preferred method of plating, a vacuum impregnation is performed
immediately
after compaction and prior to electroplating. This impregnation involves
infusion of the
formed projectile cores in methacrylate material in a large bateh type
operation. The
impregnation step reduces the porosity of the projectiles by filling voids'at
or near the
surface of the projectiles. These voids can contain impurities which might
cause corrosion
and plate fouling. The impregnation step also provides a barrier to prevent
collection of
plate bath chemicals in the recesses. Such collected chemicals could leach
through the
plating, discoloring and changing the dimensions of the bullet.
After sealing the surface of the projectiles, they can be plated with
jacketing
material to deposit the desired thickness of plating metal on the projectiles.
Acid copper
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
9
plating is preferably used, which is faster and more environmentally friendly
than
alternative techniques, such as cyanide copper plating. After jacketing, the
projectiles can
be sized using customary techniques and fabricated into cartridges.
In addition to the protective benefits obtained by adding a jacket to the
projectiles
of the present invention, the additional mass of the jacket aids in the
functionality and '
reliability of the projectiles wheri used with semi-automatic and fully
automatic firearins.
Such firearms require that a minimal impulse be delivered to the gun, slide
for operation,
and the mass added by a jacket (approximately 5-10% increase) can provide
enough mass
for the use of the projectiles of the present invention with these firearms.
The projectiles of the present invention can have a variety of configurations,
including shot and bullets, but are preferably formed into bullets for use
with firearms.
The bullets can have noses of various profiles, including round nose, soft
nose, or hollow
point. Either the bullet or the jacket, if so provided, can include a driving
band which
increases the accuracy of individual bullets and reduces the dispersion of
multiple bullets.
The invention is further illustrated by the following specific examples, in
which
parts and percentages are by weight or volume, as indicated in the Tables. The
examples
show various projectiles of the present invention, fabricated according to the
process
described herein. For each of the examples, the frangible projectiles can be
made non
frangible by heat treatment, for example, sintering. Furthermore,
representative projectiles
for each of the group of examples were fabricated into 9mm and .223 caliber
bullets, fired
and evaluated.
EXAMPLES 1-10
In Examples 1-10, frangible bullets are prepared from blends of high ductility
metal powders, namely tin (Sn), and low ductility nietal powders, namely iron
(Fe), in the
weight percentages indicated in Table I. The theoretical density of each blend
is
determined, and is also reported in Table I. In each Example, the blend has a
theoretical
density of less than lead. The high ductility metal powder has a particle size
distribution
of about 14% by weight of particles of about 45 m, about 48% by weight of
particles
having a particle size of about 75 m, about 28% by weight of particles having
a particle
size of about 105 m, about 7% by weight of particles having a particle size of
about
150 m, and about 3% by weight of particles having a particle size of about 180
.m. The
low ductility metal powder has a particle size distribution of about 22% by
weight of
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
particles up to about 44 m, about 68% by weight of particles having a
particle size of
about from 44 to 149 m, and about 10% by weight of particles having a
particle size of
about from 149 to 250 m.
The powders are intimately blended with 0.15 weight percent zinc stearate
using
5 apparatus conventionally used for the handling of metal powders. The blends
are cold
compacted at a pressure of 90,000 psi for 0.15 second on a rotary dial press.
The bullets
are jacketed with copper by electroplating. The bullets are then loaded into
cartridges,
tested and evaluated, and provide excellent perfonnance characteristics.
EXAMPLES 11-63
10 In Examples 11-63, the general procedure of Examples 1-10 is repeated,
using
blends of zinc (Zn) and iron. The specific blends and their theoretical
densities are
reported in Tables II and III. The resulting bullets are loaded into
cartridges and
evaluated, and found to provide excellent performance characteristics.
EXAMPLES 64-107
In Examples 64-107, the general procedure of Exainple 1-10 is repeated, using
blends of tin and iron. The specific blends and their theoretical densities
are reported in
Table IV. The resulting bullets are loaded into cartridges and evaluated, and
found to
provide excellent performance characteristics.
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
11
TABLE I
Density
Element A Sn 0.264
Element B Fe 0.275
Example VolA/Vo1B %Wt.A %Wt.B Wt A/ Wt B Th Dens (lbm/in^3)
1 0.50 32.43% 67.57 0.480 0.2713
2 0.75 41.86% 58.14% 0.720 0.2703
3 1.00 48.98% 51.02% 0.960 0.2695
4 1.50 59.02% 40.98% 1.440 0.2684
2.00 65.75% 34.25% 1.920 0.2677
6 3.00 74.23% 25.77% 2.880 0.2668
7 4.00 79.34% 20.66% 3.840 0.2662
8 5.00 82.76% 17.24% 4.800 0.2658
9 6.00 85.21 % 14.79% 5.760 0.2656
1.94 65.06% 34.94% 1.862 0.2677
TABLE II
Density
Element A Zn 0.259
Element B Fe 0.275
Example VoIA/VoIB %Wt.A %Wt.B Wt A/ Wt B Th Dens (lbm/in^3)
11 0.50 32.01% 67.99% 0.471 0.2697
12 0.75 41.40% 58.60% 0.706 0.2681
13 1.00 48.50% 51.50% 0.942 0.2670
14 1.50 58.55% 41.45% 1.413 0.2654
2.00 65.32% 34.68% 1.884 0.2643
16 3.00 73.86% 26.14% 2.825 0.2630
17 4.00 79.02% 20.98% 3.767 0.2622
18 5.00 82.48% 17.52% 4.709 0.2617
19 6.00 84.96% 15.04% 5.651 0.2613
1.94 64.63% 35.37% 1.827 0.2644
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
12
TABLE III
Example Zinc-Iron Mix
% Wt Fe % Wt Zn Wt Zn/Wt Vol Zn/Vol=Fe Th Dens 95%th Dens
Fe
21 20.00% 80.00% 4.000 4.2472 0.262037 0.248935
22 22.00% 78.00% 3.545 3.7645 0.262346 0.249229
23 24.00% 76.00% 3.167 3.3623 0.262656 0.249523
24 26.00% 74.00% 2.846 3.0220 0.262966 0.249818
25 28.00% 72.00% 2.571 2.7303 0.263277 0.250114
26 30.00% 70.00% 2.333 2.4775 0.263589 0.250410
27 32.00% 68.00% 2.125 2.2563 0.263902 0.250707
28 34.00% 66.00% 1.941 2.0611 0.264215 0.251005
29 34.61% 65.39% 1.889 2.0061 0.264311 0.251096
30 34.62% 65.38% 1.889 2.0052 0.264313 0.251097
31 34.63% 65.37% 1.888 2.0043 0.264314 0.251099
32 34.64% 65.36% 1.887 2.0034 0.264316 0.251100
33 34.65% 65.35% 1.886 2.0025 0.264317 0.251102
34 = 34.66% 65.34% 1.885 2.0017 0.264319 0.251103
35 34.67% 65.33% 1.884 2.0008 0.264321 0.251104
36 34.68% 65.32% 1.884 1.9999 0.264322 0.251106
37 34.69% 65.31% 1.883 1.9990 0.264324 0.251107
38 34.70% 65.30% 1.882 1.9981 0.264325 0.251109
39 34.71% 65.29% 1.881 1.9972 0.264327 0.251110
40 35.00% 65.00% 1.857 1.9719 0.264372 0.251154
41 36.00% 64.00% 1.778 1.8876 0.264529 0.251303
42 38.00% 62.00% 1.632 1.7324 0.264844. 0.251602
43 40.00% 60.00% 1.500 1.5927 0.265160 0.251902
44 42.00% 58.00% 1.381 1.4663 0.265476 0.252203
45 44.00% 56.00% 1.273 1.3514 0.265793 0.252504
46 46.00% 54.00% 1.174 1.2465 0.266111 0.252806
47 48.00% 52.00% 1.083 1.1503 0.266430 0.253108
48 50.00% 50.00% 1.000 1.0618 0.267749 0.253412
49 52.00% 48.00% 0.923 0.9801 0.267070 0.253716
50 54.00% 46.00% 0.852 0.9045 0.267390 0.254021
51 56.00% 44.00% 0.786 0.8343 0.267712 0.254327
52 58.00% 42.00% 0.724 0.7689 0.268035 0.254633
53 60.00% 40.00% 0.667 0.7079 0.268358 0.254940
54 62.00% 38.00% 0.613 0.6508 0.268682 .0255248
55 64.00% 36.00% 0.562 0.5973 0.269007 0.255557
56 66.00% 34.00% 0.515 0.5470 0.269332 0.255866
57 68.00% 32.00% 0.471 0.4997 0.269659 0.256176
58 70.00% 30.00% 0.429 0.4551 0.269986 0.256487
59 72.00% 28.00% 0.389 0.4129 0.270314 0.256798
60 74.00% 26.00% 0.351 0.3731 0.270643 0.257111
61 76.00% 24.00% 0.316 0.3353 0.270972 0.257424
62 78.00% 22.00% 0.282 0.2995 0.271303 0.257738
63 80.00% 20.00% 0.250 0.2654 0.271634 0.258052
CA 02425118 2003-04-04
WO 02/46689 PCT/US01/31343
13
TABLE IV
Example Tin-Iron Mix ,
% Wt Fe % Wt Zn Wt Zn/Wt Vol Zn/Vol Fe Th Dens 95%th Dens
Fe
64 20.00% 80.00% 4.000 4.1710 0.265900 0.252605
65 22.00% 78.00% 3.545 3.6970 0.266119 0.252814
66 24.00% 76.00% 3.167 3.3020 0.266340 0.253023
67 26.00% 74.00% 2.846 2.9678 0.266560 0.253232
68 28.00% 72.00% 2.571 2.6813 0.266782 0.253442
69 30.00% 70.00% 2.333 2.4331 ' 0.267003 0.253653
70 32.00% 68.00% 2.125 2.2158 0.267225 0.253864
71 34.00% 66.00% 1.941 2.0241 0.267447 0.254075
72 34.21% 65.79% 1.923 2.0053 0.267470 0.254097
73 34.22% 65.78% 1.922 2.0044 0.267471 0.254098
74 34.23% 65.77% 1.921 2.0035 0.267472 0.254099
75 34.24% 65.76% 1.921 2.0026 0.267474 0.254100
76 34.25% 65.75% 1.920 2.001=8 0.267475 0.254101
77 34.26% 65.74% 1.919 2.0009 0.267476 0.254102
78 34.27% 65.73% 1.918 2.0000 0.267477 0.254103
79 34.28% 65.72% 1.917 1.9991 0.267478 0.254104 =
80 34.29% 65.71% 1.916 1.9982 0.267479 0.254105
81 34.30% 65.70% 1.915 1.9973 0.267480 0.254106
82 34.31% 65.69% 1.915 1.9964 0.267481 0.254107
83 35.00% 65.00% 1.857 1.9365 0.267558 0.254180
84 36.00% 64.00% 1.778 1.8538 0.267669 0.254286
85 38.00% " 62.00% 1.632 1.7013 0.267892 0.254498
86 40.00% 60.00% 1.500 1.5641 0.268116 0.254922
87 42.00% 58.00% 1.381 1.4400 0.268339 0.254922
88 44.00% 56.00% 1.273 1.3271 0.268563 0.255135
89 46.00% 54.00% 1.174 1.2241 0.268788 0.255348
90 48.00% 52.00% 1.083 1.1296 0.269012 0.255562
91 50.00% 50.00% 1.000 1.0427 0.269238 0.255776
92 52.00% 48.00% 0.923 0.9625 0.269463 0.255990
93 54.00% 46.00% 0.852 0.8883 0.269689 0.256205
94 56.00% 44.00% 0.786 0.8193 0.269915 0.256419
95 58.00% 42.00% 0.724 0.7551 0.270142 0.256635
96 60.00% 40.00% 0.667 0.6952 0.270369 0.256850
97 62.00% 38.00% 0.613 0.6391 0.270596 .0257067
98 64.00% 36.00% 0.562 0.5865 0.270824 0.257283
99 66.00% 34.00% 0.515 0.5372 0.271510 0.257500
100 68.00% 32.00% 0.471 0.4907 0.271281 0.257717
101 70.00% 30.00% 0.429 0.4469 0.271510 0.257934
102 72.00% 28.00% 0.389 0.4055 0.271739 0.258152
103 74.00% 26.00% 0.351 0.3664. 0.271969 0.258370
104 76.00% 24.00% 0.316 0.3293 0.272199 0.258589
105 78.00% 22.00% 0.282 0.2941 0.272430 0.258808
106 80.00% 20.00% 0.250 0.2607 0.272660 0.259027
