U.S. patent application number 13/945176 was filed with the patent office on 2017-06-01 for au-base bulk solidifying amorphous alloys.
The applicant listed for this patent is Crucible Intellectual Property, LLC. Invention is credited to Atakan PEKER, Jan SCHROERS.
Application Number | 20170152586 13/945176 |
Document ID | / |
Family ID | 36203309 |
Filed Date | 2017-06-01 |
United States Patent
Application |
20170152586 |
Kind Code |
A9 |
SCHROERS; Jan ; et
al. |
June 1, 2017 |
AU-BASE BULK SOLIDIFYING AMORPHOUS ALLOYS
Abstract
Compositions for forming Au-based bulk-solidifying amorphous
alloys are provided. The Au-based bulk-solidifying amorphous alloys
of the current invention are based on ternary Au--Cu--Si alloys,
and the extension of this ternary system to higher order alloys by
the addition of one or more alloying elements. Additional
substitute elements are also provided, which allow for the
tailoring of the physical properties of the Au-base
bulk-solidifying amorphous alloys of the current invention.
Inventors: |
SCHROERS; Jan; (Laguna
Beach, CA) ; PEKER; Atakan; (Aliso Viejo,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Crucible Intellectual Property, LLC |
Rancho Santa Margarita |
CA |
US |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20130299048 A1 |
November 14, 2013 |
|
|
Family ID: |
36203309 |
Appl. No.: |
13/945176 |
Filed: |
July 18, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11576922 |
Nov 6, 2007 |
8501087 |
|
|
PCT/US2005/038171 |
Oct 17, 2005 |
|
|
|
13945176 |
|
|
|
|
60619363 |
Oct 15, 2004 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y10T 428/12 20150115;
C22C 45/001 20130101; C22C 45/003 20130101 |
International
Class: |
C22C 45/00 20060101
C22C045/00 |
Claims
1. A bulk-solidifying amorphous alloy comprising Au from 25 to 75
atomic percent, Cu from 13 to 45 atomic percent, and Si from 12 to
30 atomic percent.
2. The bulk-solidifying amorphous alloy of claim 1, comprising Au
from 30 to 67 atomic percent, Cu from 19 to 40 atomic percent, and
Si from 14 to 24 atomic percent.
3. The bulk-solidifying amorphous alloy of claim 1, comprising Au
from 40 to 60 atomic percent, Cu from 24 to 36 atomic percent, and
Si from 16 to 22 atomic percent.
4. The bulk-solidifying amorphous alloy of claim 1, further
comprising Ag.
5. The bulk-solidifying amorphous alloy of claim 4, wherein the
atomic ratio of Ag to Au is up to 0.3.
6. The bulk-solidifying amorphous alloy of claim 1, further
comprising Pd.
7. The bulk-solidifying amorphous alloy of claim 6, wherein the
atomic ratio of Pd to Au is up to 0.3.
8. The bulk-solidifying amorphous alloy of claim 1, further
comprising Ni.
9. The bulk-solidifying amorphous alloy of claim 8, wherein the
atomic ratio of Ni to Cu is up to 0.3.
10. The bulk-solidifying amorphous alloy of claim 1, further
comprising P.
11. The bulk-solidifying amorphous alloy of claim 10, wherein the
atomic ratio of P to Si is up to 1.
12. The bulk-solidifying amorphous alloy of claim 1, further
comprising Be.
13. The bulk-solidifying amorphous alloy of claim 12, wherein the
atomic ratio of Be to the sum of Si and any P is up to 1.
14. The bulk-solidifying amorphous alloy of claim 1, further
comprising one or more elements selected from a group consisting of
Ge, Al, Sn, Sb, Y, and Er.
15. The bulk-solidifying amorphous alloy of claim 1, further
comprising one or more elements selected from a group consisting of
Zr, Hf, Er, and Y.
16. A bulk-solidifying amorphous alloy, wherein the
bulk-solidifying amorphous alloy is a 14 karat, 18 karat, or 20
karat gold alloy.
17. The bulk-solidifying amorphous alloy of claim 16, comprising Au
from 25 to 75 atomic percent, Cu from 13 to 45 atomic percent, and
Si from 12 to 30 atomic percent.
18. The bulk-solidifying amorphous alloy of claim 16, further
comprising one or more elements selected from a group consisting of
Ge, Al, Sn, Sb, Y, Zr, Hf, Ag, Pd, Ni, P, Be and Er.
19. An article comprising a bulk-solidifying amorphous alloy
comprising Au, Cu and Si, wherein the article has a minimum
thickness of about 1 mm and has at least 50% amorphous content by
volume, wherein the bulk-solidifying amorphous alloy has greater
than 0% atomic percent to 17% atomic percent of Si, wherein said
Au, said Cu and said Si are distributed substantially throughout
the article.
20. The article of claim 19, wherein the bulk-solidifying amorphous
alloy composition comprises a ternary Au-containing
bulk-solidifying amorphous alloy composition.
21. The article of claim 19, wherein the bulk-solidifying amorphous
alloy is at least ninety-five percent amorphous.
22. The article of claim 19, wherein the bulk-solidifying amorphous
alloy is about one hundred percent amorphous.
23. The article of claim 19, wherein the amount of Au is greater
than about 30 atomic percent in the bulk-solidifying amorphous
alloy.
24. An article comprising a bulk-solidifying amorphous alloy
comprising Au, Cu and M, wherein the article has a minimum
thickness of about 1 mm and has at least 50% amorphous content by
volume, wherein the bulk-solidifying amorphous alloy has greater
than 0 atomic percent to 17 atomic percent of said M, wherein said
Au, said Cu and said M are distributed substantially throughout the
article; and wherein said M is selected from the group consisting
of Si, Ge, Al, Sn, Sb, Y, Er, and combinations thereof.
25. The article of claim 24, wherein the bulk-solidifying amorphous
alloy comprises: (Au.sub.1-x(Ag.sub.1-y(Pd,
Pt).sub.y).sub.x).sub.a(Cu.sub.1-z(Ni, Co, Fe, Cr,
Mn).sub.z).sub.b((M.sub.1-vP.sub.v).sub.1-w(Ge, Al, Y,
Be).sub.w).sub.c wherein a is in the range of from about 31 to
about 64, b is in the range of from about 22 to about 36, and c is
in the range of from about 12 to about 26; wherein x is between
0.05 and 0.15, y is between 0 and 0.8, z is between 0 and 0.1, v is
between 0 and 0.5, and w is between 0 and 1; and wherein M is
greater than zero atomic percent to 17 atomic percent, and Y is 5
atomic percent or less.
26. The article of claim 24, wherein the alloy is a quaternary
alloy with an alloy composition chosen from one of the following
combinations of components (Au, Cu, Ag, M), (Au, Cu, P, M), and
(Au, Cu, Pd, M).
Description
FIELD OF THE INVENTION
[0001] The present invention is directed generally to novel bulk
solidifying amorphous alloy compositions, and more specifically to
Au-based bulk solidifying amorphous alloy compositions.
BACKGROUND OF THE INVENTION
[0002] Amorphous alloys (or metallic glasses) have been generally
been prepared by rapid quenching from above the melt temperatures
to ambient temperatures. Generally, cooling rates of
10.sup.5.degree. C./sec have been employed to achieve an amorphous
structure. However, at such high cooling rates, the heat can not be
extracted from thick sections, and, as such, the thickness of
articles made from amorphous alloys has been limited to tens of
micrometers in at least in one dimension. This limiting dimension
is generally referred to as the critical casting thickness, and can
be related by heat-flow calculations to the cooling rate (or
critical cooling rate) required to form an amorphous phase.
[0003] This critical thickness (or critical cooling rate) can also
be used as a measure of the processability of an amorphous alloy.
Until the early nineties, the processability of amorphous alloys
was quite limited, and amorphous alloys were readily available only
in powder form or in very thin foils or strips with critical
dimensions of less than 100 micrometers. However, in the early
nineties, a new class of amorphous alloys was developed that was
based mostly on Zr and Ti alloy systems. It was observed that these
families of alloys have much lower critical cooling rates of less
than 10.sup.3.degree. C./sec, and in some cases as low as
10.degree. C./sec. Accordingly, it was possible to form articles
having much larger critical casting thicknesses of from about 1.0
mm to as large as about 20 mm. As such, these alloys are readily
cast and shaped into three-dimensional objects, and are generally
referred to as bulk-solidifying amorphous alloys.
[0004] Another measure of processability for amorphous alloys can
be described by defining a .DELTA.Tsc (super-cooled liquid region),
which is a relative measure of the stability of the viscous liquid
regime of the alloy above the glass transition. .DELTA.Tsc is
defined as the difference between Tx, the onset temperature of
crystallization, and Tsc, the onset temperature of super-cooled
liquid region. These values can be conveniently determined by using
standard calorimetric techniques such as DSC measurements at
20.degree. C./min. For the purposes of this disclosure, Tg, Tsc and
Tx are determined from standard DSC (Differential Scanning
Calorimetry) scans at 20.degree. C./min. Tg is defined as the onset
temperature of glass transition, Tsc is defined as the onset
temperature of super-cooled liquid region, and Tx is defined as the
onset temperature of crystallization. Other heating rates such as
40.degree. C./min, or 10.degree. C./min can also be utilized while
the basic physics of this technique are still valid. All the
temperature units are in .degree. C. Generally, a larger .DELTA.Tsc
is associated with a lower critical cooling rate, though a
significant amount of scatter exists at .DELTA.Tsc values of more
than 40.degree. C. Bulk-solidifying amorphous alloys with a
.DELTA.Tsc of more than 40.degree. C., and preferably more than
50.degree. C., and still more preferably a .DELTA.Tsc of 70.degree.
C. and more are very desirable because of the relative ease of
fabrication.
[0005] Another measure of processability is the effect of various
factors on the critical cooling rate. For example, the level of
impurities in the alloy. The tolerance of chemical impurities, such
as oxygen, can have a major impact on the critical cooling rate,
and, in turn, the ready production of bulk-solidifying amorphous
alloys. Amorphous alloys with less sensitivity to such factors are
preferred as having higher processability.
[0006] Although a number of different bulk-solidifying amorphous
alloy formulations have been disclosed based on these principals,
none of these formulations have been based on Au. Accordingly, a
need exists to develop Au-based bulk solidifying amorphous alloys
capable of use as precious metals.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to Au-based
bulk-solidifying amorphous alloys.
[0008] In one exemplary embodiment, the Au-based alloys have a
minimum Au content of more than 75% by weight.
[0009] In one exemplary embodiment, the Au-based alloys are based
on ternary Au--Cu--Si alloys.
[0010] In another exemplary embodiment, the Au--Cu--Si ternary
system is extended to higher alloys by adding one or more alloying
elements.
DESCRIPTION OF THE INVENTION
[0011] The present invention is directed to Au-based amorphous
alloys (metallic glasses) and particularly bulk-solidifying
amorphous alloys (bulk metallic glasses), which are referred to as
Au-based alloys herein.
[0012] The term "amorphous or bulk-solidifying amorphous" as used
herein in reference to the amorphous metal alloy means that the
metal alloys are at least fifty percent amorphous by volume.
Preferably the metal alloy is at least ninety-five percent
amorphous, and most preferably about one hundred percent amorphous
by volume.
[0013] The Au-based alloys of the current invention are based on
ternary Au-based alloys and the extension of this ternary system to
higher order alloys by the addition of one or more alloying
elements. Although additional components may be added to the
Au-based alloys of this invention, the basic components of the
Au-base alloy system are Au, Cu, and Si.
[0014] Within these ternary alloys the gold content can be varied
to obtain 14 karat, 18 karat, and 20 karat gold alloys, the typical
Au content in common use of jewelry applications. In one preferred
embodiment of the invention, the Au-based alloys have a minimum of
Au content more than 75% by weight.
[0015] Although a number of different Au--Cu--Si combinations may
be utilized in the Au-based alloys of the current invention, to
increase the ease of casting such alloys into larger bulk objects,
and for increased processability, the Au-based alloys comprise a
mid-range of Au content from about 25 to about 75 atomic
percentage, a mid range of Cu content from about 13 to about 45
atomic percentage, and a mid range of Si content from about 12 to
about 30 atomic percent are preferred. Accordingly, in one
embodiment of the invention, the Au-based alloys of the current
invention comprise Au in the range of from about 30 to about 67
atomic percentage; Cu in the range of from about 19 to about 40
atomic percentage; and Si in the range of from about 14 to about 24
atomic percentage. Still more preferable is a Au-based alloy
comprising a Au content from about 40 to about 60 atomic percent, a
Cu content from about 24 to about 36 atomic percentage, and a Si
content in the range of from about 16 to about 22 atomic
percentage. (All the following composition values and ratios use
atomic percentage unless otherwise stated.)
[0016] As discussed above, other elements can be added as alloying
elements to improve the ease of casting the Au-based alloys of the
invention into larger bulk amorphous objects, to increase the
processability of the alloys, or to improve its mechanical
properties and to influence its appearance. They can be divided
into three groups. One is the partial substitution of Au, another
group for Cu and then still another group is for partial
substitution of Si. In such an embodiment, Ag is a highly preferred
additional alloying element. Applicants have found that adding Ag
to the Au-based alloys of the current invention improve the ease of
casting the alloys into larger bulk objects and also increase the
supercooled liquid region of the alloys. When Ag is added, it
should be added at the expense of Au, where the Ag to Au ratio can
be up to 0.3 and a preferable range of Ag to Au ratio is in the
range of from about 0.05 to about 0.2. Ag also increases the glass
transition temperature and thereby the ease of forming the alloy
into larger bulk objects.
[0017] Another highly preferred additive alloying element is Pd.
When Pd is added, it should be added at the expense of Au, where
the Pd to Au ratio can be up to 0.3. A preferable range of Pd to Au
ratio is in the range of from about 0.05 to about 0.2. Pd also
increases the glass transition temperature and thereby the ease of
forming the alloy into larger bulk objects. Pd is also used to
increase the thermal stability of the alloy, and thereby increases
the ability to hot form the alloy in the supercooled liquid region.
Pt has a similar effect on processibility and properties of the
Au-based alloy, and should be added in a similar way as above
discussed for Pd. In addition, any combination of the two elements
is also part of the current invention.
[0018] Ni is another preferred additive alloying element for
improving the processability of the Au-based alloys of the current
invention. Ni should be treated as a substitute for Cu, and when
added it should be done at the expense of Cu. The ratio of Ni to Cu
can be as high as 0.3. A preferred range for the ratio of Ni to Cu
ratio is in the range of from about 0.05 to about 0.02. Co, Fe and
Mn and Cr have similar effects on the processibility and properties
of the Au-based alloy, and should be added in a similar way as
discussed above for Ni. Any combination of the elements is also
part of the current invention.
[0019] P is another preferred additive alloying element for
improved the processability of the Au-based alloys of the current
invention. P addition should be done at the expense of Si, where
the P to Si ratio can be up to about 1.0. Preferably, the P to Si
ratio is less than about 0.6 and even more preferable the P to Si
ratio is less than 0.3.
[0020] Be is yet another additive alloying element for improving
the processability, and for increasing the thermal stability of the
Au-based alloys of the current invention in the viscous liquid
regime above the glass transition. Be should be treated as similar
to Si, and when added it should be done at the expense of Si and/or
P, where the ratio of Be to the sum of Si and P ratio can be up to
about 1.0. Preferably, the ratio of Be to the sum of Si and P is
less than about 0.5.
[0021] It should be understood that the addition of the above
mentioned additive alloying elements may have a varying degree of
effectiveness for improving the processability in the spectrum of
alloy composition range described above and below, and that this
should not be taken as a limitation of the current invention. It
should also be understood that the addition of additives even
though individually discussed are in some cases most effective when
combined in select combinations. For example, the Au-alloy
containing Au--Cu--Ag--Pd--Si--Be has a high hardness, but
Au--Cu--Pd--Si--Be has a larger thermal stability. Therefore, the
current invention also comprises the combination of the discussed
alloy additives.
[0022] The Ag, Pd, Ni, P and Be additive alloying elements can also
improve certain physical properties such as hardness, yield
strength and glass transition temperature. A higher content of
these elements in the Au-based alloys of the current invention is
preferred for alloys having higher hardness, higher yield strength,
and higher glass transition temperature.
[0023] Other alloying elements that may be used to replace Si or
the other replacement elements for Si are Ge, Al, Sn, Sb, Y, Er.
The ratio of Si to replacement elements can improve processability
and also the cosmetics and color of those alloys. These elements
can be used as a fractional replacement of Si or elements that
replace Si. When added it should be done at the expense of Si or
the Si replacements where the ratio of any combination of Ge, Al,
Sn, Sb, Y, Er to Si can be up to about 1.0. Preferably, the ratio
is less than about 0.5.
[0024] Another group of alloy additions may be added only in small
quantities where any combination of this group will not exceed 3%.
It can be as little as 0.02%. These elements are Zr, Hf, Er, Y
(here as a replacement for Au and Cu), Sc, and Ti. These additions
improve the ease of forming amorphous phase by reducing the
detrimental effects of incidental impurities in the alloy.
[0025] Additions in small quantities, typically less than 2% that
influence the color of the alloy are also included in the current
invention. Alloy additions are limited to elements that do not
limit the critical casting thickness of the alloy to less than 1
mm.
[0026] Other alloying elements can also be added, generally without
any significant effect on processability when their total amount is
limited to less than 2%. However, a higher amount of other elements
can cause the degrading of processability, especially when compared
to the processability of the exemplary alloy compositions described
below. In limited and specific cases, the addition of other
alloying elements may improve the processability of alloy
compositions with marginal critical casting thicknesses of less
than 1.0 mm. It should be understood that such alloy compositions
are also included in the current invention.
[0027] Given the above discussion, in general, the Au-base alloys
of the current invention can be expressed by the following general
formula (where a, b, c are in atomic percentages and x, y, z, v,
and w are in fractions of whole):
(Au.sub.1-x(Ag.sub.1-y(Pd, Pt).sub.y).sub.x).sub.a(Cu.sub.1-z(Ni,
Co, Fe, Cr, Mn).sub.z).sub.b((Si.sub.1-vP.sub.v).sub.1-w(Ge, Al, Y,
Be).sub.w).sub.c
where a is in the range of from about 25 to about 75, b is in the
range of about 10 to about 50, c is in the range of about 12 to
about 30 in atomic percentages. The following constraints are given
for the x, y, z, v, and w fraction:
[0028] x is between 0 and 0.5
[0029] y is between 0 and 1
[0030] z is between 0 and 0.5
[0031] v is between 0 and 0.5
[0032] w is between 0 and 1.
[0033] Preferably, the Au-based alloys of the current invention are
given by the formula:
(Au.sub.1-x(Ag.sub.1-y(Pd, Pt).sub.y).sub.x).sub.a(Cu.sub.1-z(Ni,
Co, Fe, Cr, Mn).sub.z).sub.b((Si.sub.1-vP.sub.v).sub.1-w(Ge, Al, Y,
Be).sub.w).sub.c
where a is in the range of from about 29 to about 70, b in the
range of about 15 to about 45, and c is in the range of about 12 to
about 30 in atomic percentages. The following constraints are given
for the x, y, z, v and w fraction:
[0034] x is between 0.0 and 0.3
[0035] y is between 0 and 0.9
[0036] z is between 0 and 0.3
[0037] v between 0 and 0.5
[0038] w between 0 and 1.
[0039] Still more preferable the Au-based alloys of the current
invention are given by the formula:
(Au.sub.1-x(Ag.sub.1-y(Pd, Pt).sub.y).sub.x).sub.a(Cu.sub.1-z(Ni,
Co, Fe, Cr, Mn).sub.z).sub.b((Si.sub.1-vP.sub.v).sub.1-w(Ge, Al, Y,
Be).sub.w).sub.c
a is in the range of from about 31 to about 64, b is in the range
of about 22 to about 36, and c is in the range of from about 12 to
about 26 atomic percentages. The following constraints are given
for the x, y, z, v and w fraction:
[0040] x is between 0.05 and 0.15
[0041] y is between 0 and 0.8
[0042] z is between 0 and 0.1
[0043] v is between 0 and 0.5
[0044] w is between 0 and 1.
[0045] For increased processability, the above mentioned alloys are
preferably selected to have four or more elemental components. The
most preferred combination of components for Au-based quaternary
alloys of the current invention are: Au, Cu, Ag and Si; Au, Cu, Si
and P; Au, Cu, Pd and Si; and Au, Cu, Si, and Be.
[0046] The most preferred combinations for five component Au-based
alloys of the current invention are: Au, Cu, Pd, Ag and Si; Au, Cu,
Ag, Si and P; Au, Cu, Pd, Si and P; Au, Cu, Ag, Si and Be; and Au,
Cu, Pd, Si and Be.
[0047] Provided these preferred compositions, a preferred range of
alloy compositions can be expressed with the following formula:
(Au.sub.1-x(Ag.sub.1-yPd.sub.y).sub.x).sub.aCu.sub.b((Si.sub.1-zBe.sub.z-
).sub.1-vP.sub.v).sub.c,
where a is in the range of from about 25 to about 75, b is in the
range of about 10 to about 50, and c is in the range of about 10 to
about 35 in atomic percentages; preferably a is in the range of
from about 39 to about 70, b is in the range of about 15 to about
45, and c is in the range of about 12 to about 30 in atomic
percentages; and still most preferably a is in the range of from
about 31 to about 64, b is in the range of about 22 to about 36,
and c is in the range of about 12 to about 26 in atomic
percentages. Furthermore, x is in the range from about 0.0 to about
0.5, y is in the range of from about 0.0 to about 1.0, z is in the
range of from about 0.0 to about 0.5, and v is in the range between
0 and 0.5; and preferably, x is in the range from about 0.0 to
about 0.3, y is in the range of from about 0 to about 0.9, z is in
the range of from about 0.0 to about 0.3, and v is in the range
between 0 and 0.5; and still more preferable x is in the range from
about 0.05 to about 0.15, y is in the range of from about 0 to
about 0.8, z is in the range of from about 0.0 to about 0.1, and v
is in the range between 0 and 0.5.
[0048] A still more preferred range of alloy compositions for
jewelry applications can be expressed with the following
formula:
(Au.sub.1-x(Ag.sub.1-yPd.sub.y).sub.x).sub.aCu.sub.bSi.sub.c,
where a is in the range of from about 25 to about 75, b is in the
range of about 10 to about 50, and c is in the range of about 12 to
about 30 in atomic percentages; preferably a is in the range of
from about 29 to about 70, b is in the range of about 15 to about
45, and c is in the range of about 13 to about 25 in atomic
percentages; and still most preferably a is in the range of from
about 31 to about 64, b is in the range of about 22 to about 36,
and c is in the range of about 14 to about 22 in atomic
percentages. Furthermore, x is in the range from about 0.0 to about
0.5, and y is in the range of from about 0.0 to about 1.0; and
preferably, x is in the range from about 0.0 to about 0.3, and y is
in the range of from about 0.0 to about 0.9, and even more
preferable x is in the range from about 0.05 to about 0.15, and y
is in the range of from about 0.0 to about 0.8.
EXAMPLES
[0049] The following alloy compositions are exemplary compositions,
which can be cast into large bulk objects of up to 4 mm in diameter
or more.
[0050] Au.sub.49Cu.sub.26.9Ag.sub.5.5Pd.sub.2.3Si.sub.16.3
[0051] Au.sub.47Cu.sub.29.8Ag.sub.4Pd.sub.2.5Si.sub.16.7
[0052]
Au.sub.48.2Cu.sub.27Ag.sub.5.5Pd.sub.2.3Si.sub.13Be.sub.4
[0053]
Au.sub.47Cu.sub.28.8Ag.sub.4Pd.sub.2.5Si.sub.16.7Zr.sub.1
[0054] The following alloy compositions are exemplary compositions,
which can be cast into large bulk objects of up to 1 mm in diameter
or more.
[0055] Au.sub.48Cu.sub.30Ag.sub.5Si.sub.17
[0056] Au.sub.55Cu.sub.30Si.sub.16P.sub.7
[0057] Au.sub.53Cu.sub.30Si.sub.13Be.sub.7
[0058] Au.sub.61Cu.sub.16.7Ag.sub.4Pd.sub.2.3Si.sub.16
[0059] Au.sub.33Cu.sub.44.7Ag.sub.4Pd.sub.2.3Si.sub.16
[0060] Finally, the invention is also directed to a method of
forming a Au-based amorphous alloy as described above. In this
embodiment the method would include forming an alloy having the
formula as described above, and then cooling the entire alloy from
above its melting temperature to a temperature below its glass
transition temperature at a sufficient rate to prevent formation of
a crystalline phase above a satisfactory level.
[0061] Although specific embodiments are disclosed herein, it is
expected that persons skilled in the art can and will design
alternative Au-based bulk solidifying amorphous alloys and methods
of making such alloys that are within the scope of the following
claims either literally or under the Doctrine of Equivalents.
* * * * *