U.S. patent application number 15/415417 was filed with the patent office on 2018-03-08 for ni-free zr-based bmgs for black hue control.
The applicant listed for this patent is Apple Inc.. Invention is credited to Naoto Matsuyuki, Theodore A. Waniuk, Yoshihiko Yokoyama.
Application Number | 20180066347 15/415417 |
Document ID | / |
Family ID | 61282023 |
Filed Date | 2018-03-08 |
United States Patent
Application |
20180066347 |
Kind Code |
A1 |
Yokoyama; Yoshihiko ; et
al. |
March 8, 2018 |
NI-FREE ZR-BASED BMGS FOR BLACK HUE CONTROL
Abstract
The disclosure provides nickel free Zr--Cu--Al metallic
glass-forming alloys and metallic glasses comprising at least of
Pt, Pd, and Co where the atomic fraction of Zr ranges from 50 to
70, the atomic fraction of Cu ranges from 15 to 45, the atomic
fraction of Al ranges from 5 to 15, and the combined atomic
fraction of Pt, Pd, and Co ranges from 1 to 10.
Inventors: |
Yokoyama; Yoshihiko; (Tokyo,
JP) ; Waniuk; Theodore A.; (Lake Forest, CA) ;
Matsuyuki; Naoto; (Kasugai-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Family ID: |
61282023 |
Appl. No.: |
15/415417 |
Filed: |
January 25, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62384473 |
Sep 7, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C22C 1/002 20130101;
C22C 45/10 20130101; C22F 1/002 20130101; C22F 1/186 20130101 |
International
Class: |
C22C 45/10 20060101
C22C045/10; C22F 1/00 20060101 C22F001/00; C22F 1/18 20060101
C22F001/18 |
Claims
1. A metallic glass-forming alloy having a composition represented
by the following formula (subscripts denote atomic percentages):
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bX.sub.c where: X is at least one
of Pt, Pd, and Co a ranges from 15 to 45 at %; b ranges from 5 to
15 at %; c ranges from 1 to 10 at %; wherein the critical rod
diameter of the metallic glass-forming alloy is at least 1 mm, and
wherein a thermal stability of the supercooled liquid of the
composition is at least 70 K.
2. The metallic glass-forming alloy of claim 1 wherein the atomic
fraction of Zr ranges from 55 to 65 at %.
3. The metallic glass-forming alloy of claim 1 wherein the atomic
fraction of Cu ranges from 15 to 40 at %.
4. The metallic glass-forming alloy of claim 1 wherein b is 8 to 12
at %.
5. The metallic glass-forming alloy of claim 1 wherein a is from 18
to 38, b is from 8 to 12, and c is from 2 to 7.
6. The metallic glass-forming alloy of claim 1 wherein X is Pt.
7. The metallic glass-forming alloy of claim 6 wherein a is from 18
to 31, b is from 8 to 12, and c is from 2 to 7.
8. The metallic glass-forming alloy of claim 7 wherein the alloy
has a brightness L*from 35 to 50, an a* value from -0.1 to 1, and a
b* value from -0.25 to +5.
9. The metallic glass-forming alloy of claim 1 wherein X is Pd or
Pt.
10. The metallic glass-forming alloy of claim 9 wherein a ranges
from 18 to 35, b is from 8 to 12, and c ranges from 2 to 7.
11. The metallic glass-forming alloy of claim 10 wherein the alloy
has a brightness L* from 36 to 444, an a* value from -0.5 to 0.5,
and a b* value from -5.25 to 1.
12. The metallic glass-forming alloy of claim 8 wherein a is from
18 to 38, b is from 8 to 12, and c is from 2 to 7.
13. The metallic glass-forming alloy of claim 13 wherein the alloy
has a brightness L* from 35 to 45, an a* value from -0.3 to 0.25,
and a b* value from -4.5 to 6.
14. A metallic glass comprising an alloy where a composition of the
alloy is represented by the following formula (subscripts denote
atomic percentages): Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bX.sub.c
where: a ranges from 15 to 45; b ranges from 5 to 15; c ranges from
1 to 10; where X can is selected from at least one of Pd, Pt, Co,
and a combinations thereof.
15. The metallic glass of claim 14 wherein a ranges from 15 to
40.
16. The metallic glass of claim 14 wherein a ranges from 18 to 38,
b is 10, and c ranges from 2 to 7.
17. A method of producing the metallic glass comprising: melting an
alloy into a molten state; where the alloy has a composition
represented by the following formula (subscripts denote atomic
percentages): Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bX.sub.c where: a
ranges from 15 to 45; b ranges from 5 to 15; c ranges from 1 to 10;
where X can is selected from at least one of Pd, Pt, Co, and a
combinations thereof; and quenching the melt at a cooling rate
sufficiently rapid to prevent crystallization of the alloy.
18. The method of claim 17 wherein the atomic fraction of Cu ranges
from 15 to 40 at %.
19. The method of claim 17, further comprising fluxing the melt
with a reducing agent prior to quenching.
20. The method of claim 17 wherein the temperature of the melt
prior to quenching is at least 1100.degree. C.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This patent application claims the benefit of U.S. Patent
Application No. 62/384,473, entitled "NI-FREE ZR-BASED BMGS FOR
BLACK HUE CONTROL," filed on Sep. 7, 2016 under 35 U.S.C.
.sctn.119(e), which is incorporated herein by reference in its
entirety.
FIELD
[0002] The described embodiments relate generally to Ni-free
Zirconium based metallic glass. More particularly, the present
embodiments relate to eutectic and hypoeutectic Zr--Cu--Al alloys
and metallic glasses including Pt, Pd, and/or Co having good
glass-forming ability and high resistivity against structural
relaxation embrittlement (high thermal stability). These alloys,
therefore, can make black coloring by annealing in air
(oxidization) while maintaining mechanical properties.
BACKGROUND
[0003] Metallic glasses are metallic alloys that do not have a
crystalline structure. Instead, like glass, their structure is
amorphous. Metallic glasses have a number of beneficial material
properties that make them viable for use in a number of engineering
applications. Some of the properties of metallic glasses include
high strength, elasticity, corrosion resistance and processability
from the molten state.
SUMMARY
[0004] The disclosure provides hypoeutectic Ni-Free
Zr--Cu--Al--(Pd, Pt) bulk metallic glasses (BMGs). The performance
of these alloys is better than other published Zr-Based BMGs from
the standpoint of biocompatibility, glass-forming ability,
resistance to embrittlement due to both structural relaxation and
oxygen absorption, and oxide layer formation.
[0005] The disclosure provides nickel-free Zirconium (Zr) metallic
glass-forming alloys and metallic glasses comprising Zr--Cu--Al
with at least of one of Pd, Pt, and Co, where the atomic percent of
Zr is at least 50, the atomic percent of Cu ranges from 15 to 45,
the atomic percent of Al ranges from 5 to 15, and the combined
atomic percent of Pd, Pt, and Co range from 1 to 15.
[0006] In another embodiment, the disclosure is directed to an
alloy capable of forming a metallic glass having a composition
represented by the following formula (subscripts denote atomic
percentages):
Zr(.sub.100-a-b-c)Cu.sub.aAl.sub.bX.sub.c [0007] Where X is at
least one of Pd, Pt, Co, where: [0008] a ranges from 15 to 45;
[0009] b ranges from 5 to 15; [0010] c ranges from 1 to 10; and
[0011] wherein the Zr atomic fraction ranges from 50 to 70.
[0012] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 50 to 65.
[0013] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 57 to 65.
[0014] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 50 to 55.
[0015] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 15 to 40.
[0016] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 18 to 40.
[0017] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 18 to 30.
[0018] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 33 to 40.
[0019] In another embodiment of the metallic glass-forming alloy or
metallic glass, b ranges from 9 to 11.
[0020] In another embodiment of the metallic glass-forming alloy or
metallic glass b, is 10.
[0021] In another embodiment of the metallic glass-forming alloy or
metallic glass, c ranges from 1 to 8.
[0022] In another embodiment of the metallic glass-forming alloy or
metallic glass, c ranges from 2 to 7.
[0023] In another embodiment of the metallic glass-forming alloy or
metallic glass, the ratio of Zr/Cu is 1 to 2.
[0024] In another embodiment of the metallic glass-forming alloy or
metallic glass, the ratio of Zr/Cu is 1.1 to 1.6.
[0025] In another embodiment, the thermal stability of the
supercooled liquid is at least 70 K.
[0026] In another embodiment, the thermal stability of the
supercooled liquid is at least 80 K.
[0027] In another embodiment, the thermal stability of the
supercooled liquid is at least 85 K.
[0028] In another embodiment, the thermal stability of the
supercooled liquid is at least 90 K.
[0029] In another embodiment, metallic glass-forming alloy or
metallic glass has a hardness of at least 400 HV.
[0030] In another embodiment, the disclosure is directed to an
alloy capable of forming a metallic glass having a composition
represented by the following formula (subscripts denote atomic
percentages):
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bPt.sub.c [0031] where: [0032] a
ranges from 18 to 38; [0033] b ranges from 9 to 11; [0034] c ranges
from 2 to 7; and [0035] wherein the Zr atomic fraction ranges from
50 to 70.
[0036] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 57 to 65.
[0037] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 18 to 31.
[0038] In another embodiment of the metallic glass-forming alloy or
metallic glass, b is 10.
[0039] In another embodiment of the metallic glass-forming alloy or
metallic glass, the thermal stability of the supercooled liquid
.DELTA.Tx is at least 30.degree. C.
[0040] In another embodiment, the metallic glass-forming alloy or
metallic glass has a hardness of at least 450 HV.
[0041] In another embodiment, the metallic glass-forming alloy or
metallic glass has a hardness of at least 485 HV.
[0042] In another embodiment, the disclosure is directed to an
alloy capable of forming a metallic glass having a composition
represented by the following formula (subscripts denote atomic
percentages):
Zr(.sub.100-a-b-c)Cu.sub.aAl.sub.bPd.sub.c [0043] where: [0044] a
ranges from 18 to 35; [0045] b ranges from 9 to 11; [0046] c ranges
from 0.5 to 7; and [0047] wherein the Zr atomic fraction ranges
from 50 to 70.
[0048] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 53 to 55.
[0049] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 57 to 65.
[0050] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 59 to 60.
[0051] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 33 to 35.
[0052] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 18 to 28.
[0053] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 18 to 22.
[0054] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 23 to 28.
[0055] In another embodiment of the metallic glass-forming alloy or
metallic glass, b is 10.
[0056] In another embodiment of the metallic glass-forming alloy or
metallic glass, c ranges from 0.5 to 7.
[0057] In another embodiment of the metallic glass-forming alloy or
metallic glass, c ranges from 1 to 2.
[0058] In another embodiment of the metallic glass-forming alloy or
metallic glass, c ranges from 3 to 7.
[0059] In another embodiment of the metallic glass-forming alloy or
metallic glass is the thermal stability of the supercooled liquid
.DELTA.Tx is at least 24.degree. C.
[0060] In another embodiment, the metallic glass-forming alloy or
metallic glass has a hardness of at least 400 HV.
[0061] In another embodiment, the metallic glass-forming alloy or
metallic glass has a hardness of at least 425 HV.
[0062] In another embodiment, the metallic glass-forming alloy or
metallic glass has a hardness of at least 450 HV.
[0063] In another embodiment, the disclosure is directed to an
alloy capable of forming a metallic glass having a composition
represented by the following formula (subscripts denote atomic
percentages):
Zr(.sub.100-a-b-c)Cu.sub.aAl.sub.bCo.sub.c [0064] where: [0065] a
ranges from 19.5 to 38; [0066] b ranges from 9 to 11; [0067] c
ranges from 2 to 7; and [0068] wherein the Zr atomic fraction
ranges from 50 to 70.
[0069] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 50 to 55.
[0070] In another embodiment of the metallic glass-forming alloy or
metallic glass, the atomic percent of Zr ranges from 57 to 65.
[0071] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 19.5 to 40.
[0072] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 18 to 30.
[0073] In another embodiment of the metallic glass-forming alloy or
metallic glass, a ranges from 33 to 40.
[0074] In another embodiment of the metallic glass-forming alloy or
metallic glass, the thermal stability of the supercooled liquid
.DELTA.Tx is at least 70.degree. C.
[0075] In another embodiment, the metallic glass-forming alloy or
metallic glass has a hardness of at least 400 HV.
[0076] In another embodiment, the metallic glass-forming alloy or
metallic glass has a hardness of at least 425 HV.
[0077] The disclosure is also directed to a method of forming a
metallic glass, or an article made of a metallic glass from the
metallic glass-forming alloy, comprising: heating and melting an
ingot comprising the metallic glass-forming alloy under inert
atmosphere to create a molten alloy, and subsequently quenching the
molten alloy fast enough to avoid crystallization of the molten
alloy.
[0078] In one embodiment, prior to quenching, the molten alloy is
heated to at least 100.degree. C. above the liquidus temperature of
the metallic glass-forming alloy.
[0079] In another embodiment, prior to quenching, the molten alloy
is heated to at least 200.degree. C. above the liquidus temperature
of the metallic glass-forming alloy.
[0080] In yet another embodiment, prior to quenching, the molten
alloy is heated to at least 1100.degree. C.
[0081] In yet another embodiment, prior to quenching, the molten
alloy is heated to at least 1200.degree. C.
[0082] In yet another embodiment, the melt of the alloy is fluxed
with a reducing agent prior to forming a metallic glass.
[0083] In yet another embodiment, the reducing agent is boron
oxide.
[0084] In yet another embodiment, the temperature of the melt prior
to quenching to form a metallic glass is at least at the liquidus
temperature of the alloy.
[0085] The disclosure is further directed to a metallic glass
according to any of the above formulas and/or formed of any of the
foregoing alloys.
[0086] The disclosure is also directed to an alloy or a metallic
glass having compositions selected from a group consisting of
Zr.sub.57Cu.sub.31Al.sub.10Pt.sub.2,
Zr.sub.57Cu.sub.30Al.sub.10Pt.sub.3,
Zr.sub.60Cu.sub.27Al.sub.10Pt.sub.3,
Zr.sub.60Cu.sub.25Al.sub.10Pt.sub.5,
Zr.sub.60Cu.sub.23Al.sub.10Pt.sub.7,
Zr.sub.60Cu.sub.22Al.sub.10Pt.sub.3,
Zr.sub.60Cu.sub.20Al.sub.10Pt.sub.5,
Zr.sub.60Cu.sub.18Al.sub.10Pt.sub.7,
Zr.sub.53Cu.sub.35Al.sub.10Pd.sub.2,
Zr.sub.55Cu.sub.33Al.sub.10Pd.sub.2,
Zr.sub.55Cu.sub.24.5Al.sub.10Co.sub.1Pd.sub.3,
Zr.sub.60Cu.sub.24.5Al.sub.10Co.sub.5Pd.sub.0.5,
Zr.sub.65Cu.sub.19.5Al.sub.10Co.sub.5Pd.sub.0.5,
Zr.sub.57Cu.sub.30Al.sub.10Pd.sub.3,
Zr.sub.59Cu.sub.28Al.sub.10Pd.sub.3,
Zr.sub.60Cu.sub.27Al.sub.10Pd.sub.3,
Zr.sub.60Cu.sub.25Al.sub.10Pd.sub.5,
Zr.sub.60Cu.sub.23Al.sub.10Pd.sub.7,
Zr.sub.65Cu.sub.22Al.sub.10Pd.sub.3,
Zr.sub.65Cu.sub.20Al.sub.10Pd.sub.5,
Zr.sub.65Cu.sub.18Al.sub.10Pd.sub.7,
Zr.sub.50Cu.sub.38Al.sub.10Co.sub.2,
Zr.sub.53Cu.sub.35Al.sub.10Co.sub.2,
Zr.sub.55Cu.sub.35Al.sub.10Co.sub.2,
Zr.sub.55Cu.sub.33Al.sub.10Co.sub.1Pd.sub.1,
Zr.sub.57Cu.sub.30Al.sub.10Co.sub.3,
Zr.sub.57Cu.sub.28Al.sub.10Co.sub.5,
Zr.sub.60Cu.sub.27Al.sub.10Co.sub.3,
Zr.sub.60Cu.sub.25Al.sub.10Co.sub.5,
Zr.sub.60Cu.sub.23Al.sub.10Co.sub.5Pd.sub.0.5,
Zr.sub.65Cu.sub.22Al.sub.10Co.sub.3,
Zr.sub.65Cu.sub.20Al.sub.10Co.sub.5,
Zr.sub.65Cu.sub.18Al.sub.10Co.sub.7, and
Zr.sub.65Cu.sub.19.5Al.sub.10Co.sub.5Pd.sub.0.5.
DETAILED DESCRIPTION
[0087] The disclosure is directed to Ni-free Zr--Cu--Al based
metallic glass including at least one of Pt, Pd, and Co having high
resistivity against structural relaxation embrittlement and having
a dark color (e.g., grey or black). The disclosure provides
Zr--Cu--Al metallic glass-forming alloys and metallic glasses that
have a high glass-forming ability along with a high thermal
stability of the supercooled liquid against crystallization. The
Zr--Cu--Al alloys further include at least one of Pt, Pd, Co, or
combinations thereof.
[0088] As described herein, the term "Ni-free" refers to equal to
or less than the amount of Ni in naturally occurring abundance. It
will be recognized that in all alloys (including metallic glasses)
described herein that the alloys can include incidental impurities
equal to or less than natural abundance. In the context of this
disclosure, an alloy being free of a certain element means that the
concentration of that element in the alloy is consistent with the
concentration of an incidental impurity. In the context of this
disclosure, the concentration of a certain element in an alloy
being 0 means that the concentration of that element is consistent
with the concentration of an incidental impurity. The term
"Ni-free" means that there is no Ni beyond the Ni-impurity that is
present in raw materials. In various embodiments, the concentration
of an incidental impurity is less than 2 atomic percent. In some
embodiments, the concentration of an incidental impurity is less
than 1 atomic percent, in other embodiments is less than 0.5 atomic
percent, while in yet other embodiments is less than 0.1 atomic
percent.
[0089] Reference will now be made in detail to representative
embodiments illustrated in the accompanying drawings. It should be
understood that the following descriptions are not intended to
limit the embodiments to one preferred embodiment. To the contrary,
it is intended to cover alternatives, modifications, and
equivalents as can be included within the spirit and scope of the
described embodiments as defined by the appended claims.
[0090] A "critical cooling rate," which is defined as the cooling
rate required to avoid crystallization and form the amorphous phase
of the metallic glass-forming alloy (i.e. the metallic glass),
determines the critical plate thickness. The lower the critical
cooling rate of a metallic glass-forming alloy, the larger its
critical plate thickness. The critical cooling rate R.sub.c in K/s
and critical plate thickness t.sub.c in mm are related via the
following approximate empirical formula:
R.sub.c=1000/t.sub.c.sup.2 Eq. (1)
According to Eq. (1), the critical cooling rate for a metallic
glass-forming alloy having a critical casting thickness of about 1
mm is about 10.sup.3 K/s.
[0091] Generally, three categories are known in the art for
identifying the ability of an alloy to form a metallic glass (i.e.
to bypass the stable crystal phase and form an amorphous phase).
Alloys having critical cooling rates in excess of 1012 K/s are
typically referred to as non-glass formers, as it is physically
impossible to achieve such cooling rates over a meaningful
thickness. Alloys having critical cooling rates in the range of 105
to 1012 K/s are typically referred to as marginal glass formers, as
they are able to form metallic glass foils or ribbons with
thicknesses ranging from 1 to 100 micrometers according to EQ. (2).
Metal alloys having critical cooling rates on the order of 103 or
less, and as low as 1 or 0.1 K/s, are typically referred to as bulk
glass formers, as they are able to form metallic glass plates with
thicknesses ranging from 1 millimeter to several centimeters. The
glass-forming ability of a metallic alloy is, to a very large
extent, dependent on the composition of the metallic glass-forming
alloy. The compositional ranges for alloys that are marginal glass
formers are considerably broader than those which are bulk glass
formers.
[0092] Often in the art, a measure of glass-forming ability of an
alloy is reported as the "critical rod diameter," defined as the
largest rod diameter in which the amorphous phase can be formed
when processed by a method of water quenching a quartz tube having
0.5 mm thick walls containing a molten alloy.
[0093] In the present disclosure, the thermal stability of the
supercooled liquid .DELTA.Tx is defined as the difference between
the crystallization temperature Tx and the glass transition
temperature Tg of the metallic glass, .DELTA.Tx=Tx-Tg, measured by
calorimetry at a heating rate of 20 K/min.
[0094] The thermal stability of the supercooled liquid .DELTA.Tx is
a property defining the ability of the metallic glass to be shaped
"thermoplastically" in the supercooled liquid region, i.e. to be
shaped by heating the metallic glass to a softening temperature To
above the glass transition temperature Tg, applying a deformational
force to shape the metallic glass over a time to that is shorter
than the time it takes for the softened metallic glass to
crystallize at To, and cooling the metallic glass to a temperature
below Tg. The higher the thermal stability of the supercooled
liquid .DELTA.Tx, the longer the available time to shape, which
would allow application of the deformational force for longer
periods and thus enable larger shaping strains. Also, the higher
the thermal stability of the supercooled liquid .DELTA.Tx, the
higher the softening temperature To to which the metallic glass can
be heated, which would result in lower viscosities and thus allow
larger shaping strains.
[0095] In addition to exhibiting large thermal stability of the
supercooled liquid .DELTA.Tx, the metallic glass should be capable
of being formed in bulk (i.e. millimeter-thick) dimensions in order
to enable "thermoplastic" shaping of bulk 3-dimensional articles.
That is, metallic glasses having both a high glass-forming ability
as well as a large .DELTA.Tx would be suitable for "thermoplastic"
shaping of bulk articles. Discovering compositional regions where
the metallic glass demonstrates a high glass-forming ability is
unpredictable. Discovering compositional regions where the metallic
glass demonstrates a large .DELTA.Tx is equally unpredictable.
Discovering compositional regions where the metallic glass
demonstrates both a high glass-forming ability and a large
.DELTA.Tx is even more unpredictable than both cases above, because
metallic glasses that demonstrate a high glass-forming ability do
not necessarily demonstrate a large .DELTA.Tx, and vice versa.
[0096] In this disclosure, compositional regions in the Ni-free
Zr--Cu--Al alloy systems including at least of one of Pd, Pt, and
Co are disclosed where the metallic glass-forming alloys
demonstrate resistance against structural relaxation embrittlement,
bulk glass-forming ability, biocompatibility, and a dark color (due
to oxide layer formation).
[0097] While the role of the minor alloying element Ni in Zr-based
metallic glass-forming alloy systems is glass-forming ability
improvement, the glass-forming ability can be improved by
protection from oxidation/oxygen absorption, even in the molten
state under vacuum. Ni assists in stabilizing spontaneous formation
of a surface oxide layer, thereby protecting the alloy. In
addition, when trying to minimize structural relaxation
embrittlement, protection of the alloy bulk from oxidation/oxygen
absorption is important to maintain sufficient alloy
performance.
[0098] However, a Ni-free Zr metallic glass-forming alloy or
metallic glass composition is desirable for biocompatibility.
Therefore, alternatives to Ni in Zr-based metallic glass-forming
alloy or metallic glass composition is of interest. In the
disclosure, embodiments of the metallic glass-forming alloy or
metallic glass composition include Pd, Pt, Co, or combinations
thereof as alternatives to Ni. The addition of the minor elements
of Pd, Pt, and/or Co can increase corrosion resistance as well as
retaining good glass-forming ability. The minor elements of Pd, Pt,
and/or Co can also help to stabilize oxide layer formation.
Additionally, the oxidation layer can affect the color/hue and/or
wear resistances of the metallic glass-forming alloy or metallic
glasses. A normal oxidized color surface of metallic glasses is not
black. For example, Zr-based bulk metallic glasses (BMGs), such as
LM105 provided by Liquid Metal, are in blue color after
oxidization. However, by controlling the atomic concentration of
Pd, Pt, and/or Co, the formation of an oxide layer can be
controlled, thereby the color/hue and/or wear resistance can be
controlled.
[0099] Also, embrittlement of Zr-based metallic glass-forming
alloys and metallic glasses is caused by both oxygen/hydrogen
absorption and structural relaxation (through annealing/aging). As
discussed above, the oxygen/hydrogen absorption can be controlled
using Pd, Pt, Co or combinations thereof as minor elements in the
Zr-based metallic glass-forming alloys and metallic glasses.
Additionally, adjusting the alloy composition to be eutectic (i.e.
at least 50 atomic percent Zr) or hypoeutectic (i.e. at least 57
atomic percent Zr) can control the structural relaxation.
[0100] In some embodiments, the disclosure provides Zr--Cu--Al--X
metallic glass-forming alloys and metallic glasses that are
eutectic or hypoeutectic where the atomic percent of Zr is at least
50, where the atomic percent of Cu ranges from 15 to 45, where the
atomic percent of Al ranges from 5 to 15, where X is at least of
Pt, Pd, and Co, and where the combined atomic percent of Pd, Pt,
and Co range from 1-15. In some embodiments, Cu ranges from 15 to
40 in the Zr--Cu--Al--X metallic glass-forming alloy or metallic
glass.
[0101] In another embodiment, the disclosure is directed to an
alloy capable of forming a metallic glass having a composition
represented by the following formula (subscripts denote atomic
percentages):
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bX.sub.c
Where X is at least one of Pd, Pt, Co, where: a is up to 45; b is
up to 30; c is up to 30; and wherein the atomic fraction of Zr is
at least 50.
[0102] In some embodiments, a is up to 30 in the Zr--Cu--Al--X
metallic glass-forming alloy or metallic glass.
Description of Pt Bearing Ni-Free Zr--Cu--Al Alloys and Metallic
Glass Compositions
[0103] In some embodiments, the disclosure is directed to nickel
free Zr--Cu--Al metallic glass-forming alloys and metallic glasses
that also bear Pt. The disclosure is directed to metallic
glass-forming alloys and metallic glasses having a composition
represented by the following formula (subscripts denote atomic
percentages):
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bPt.sub.c
where: a ranges from 18 to 38; b ranges from 8 to 12; c ranges from
2 to 7; and wherein the Zr atomic fraction ranges from 50 to
70.
[0104] In some embodiments, the critical rod diameter of the alloy
is at least 1 mm. In another embodiment of the metallic
glass-forming alloy or metallic glass, the alloy or metallic glass
is hypoeutectic and the atomic percent of Zr ranges from 57 to 65,
a ranges from 18-31, b is 10 and c ranges from 2-7. In some
embodiments, the metallic glass-forming alloy or metallic glass has
the thermal stability of the supercooled liquid .DELTA.Tx that is
at least 30.degree. C.
[0105] In some embodiments, the metallic glass-forming alloy or
metallic glass has a hardness of at least 450 HV. In another
embodiment, the metallic glass-forming alloy or metallic glass has
a hardness of at least 485 HV.
[0106] Specific embodiments of metallic glass-forming alloys or
metallic glasses formed of Zr--Cu--Al comprising Pt with
compositions according to the formula
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bPt.sub.c are presented in Table
1. In these alloys, the atomic percent of Zr varies from 57 to 60,
the atomic percent of Cu varies from 18 to 31, and the atomic
percent of Pt varies from 2 to 7. Thermal and mechanical properties
for the specific embodiments are summarized in Table 1.
TABLE-US-00001 TABLE 1 Sample metallic glasses demonstrating the
effect of increasing Pt atomic concentration by substitution of Cu
according to the formula Zr.sub.(100
-a-b-c)Cu.sub.a-Al.sub.bPt.sub.c Example Composition T.sub.g
(.degree. C.) .DELTA.T.sub.x (.degree. C.) HV 1
Zr.sub.57Cu.sub.31Al.sub.10Pt.sub.2 2
Zr.sub.57Cu.sub.30Al.sub.10Pt.sub.3 417 74 496 .+-. 9 3
Zr.sub.60Cu.sub.27Al.sub.10Pt.sub.3 403 60 483 .+-. 8 4
Zr.sub.60Cu.sub.25Al.sub.10Pt.sub.5 419 49 475 .+-. 7 5
Zr.sub.60Cu.sub.23Al.sub.10Pt.sub.7 425 54 512 .+-. 22 6
Zr.sub.60Cu.sub.22Al.sub.10Pt.sub.3 393 33 461 .+-. 10 7
Zr.sub.60Cu.sub.20Al.sub.10Pt.sub.5 399 34 490 .+-. 11 8
Zr.sub.60Cu.sub.18Al.sub.10Pt.sub.7 418 31 499 .+-. 6
Description of Pd Bearing Ni-Free Zr--Cu--Al Alloys and Metallic
Glass Compositions
[0107] In some embodiments, the disclosure is directed to
nickel-free Zr--Cu--Al metallic glass-forming alloys and metallic
glasses that also bear Pd. The disclosure is directed to metallic
glass-forming alloys and metallic glasses having a composition
represented by the following formula (subscripts denote atomic
percentages):
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bPd.sub.c
where: a ranges from 18 to 38; b ranges from 8 to 12; c ranges from
2 to 7; and wherein the Zr atomic fraction ranges from 50 to
70.
[0108] In some embodiments, the critical rod diameter of the alloy
is at least 1 mm. In another embodiment of the metallic
glass-forming alloy or metallic glass, the atomic percent of Zr
ranges from 53 to 55. In another embodiment of the metallic
glass-forming alloy or metallic glass, the atomic percent of Zr
ranges from 57 to 65. In another embodiment of the metallic
glass-forming alloy or metallic glass, the atomic percent of Zr
ranges from 59 to 60.
[0109] In some embodiments of the metallic glass-forming alloy or
metallic glass, a ranges from 33 to 35. In another embodiment of
the metallic glass-forming alloy or metallic glass, a ranges from
18 to 28. In another embodiment of the metallic glass-forming alloy
or metallic glass, a ranges from 18 to 22. In another embodiment of
the metallic glass-forming alloy or metallic glass, a ranges from
23 to 28.
[0110] In some embodiments of the metallic glass-forming alloy or
metallic glass, c ranges from 0.5 to 7. In another embodiment of
the metallic glass-forming alloy or metallic glass, c ranges from 1
to 2. In another embodiment of the metallic glass-forming alloy or
metallic glass, c ranges from 3 to 7.
[0111] In some embodiments, the metallic glass-forming alloy or
metallic glass has a thermal stability of the supercooled liquid
.DELTA.Tx that is at least 24.degree. C. In some embodiments, the
metallic glass-forming alloy or metallic glass has a hardness of at
least 400 HV. While, in other embodiments, the metallic
glass-forming alloy or metallic glass has a hardness of at least
425 HV, while in yet other embodiments, the metallic glass-forming
alloy or metallic glass has a hardness of at least 450HV.
[0112] Specific embodiments of metallic glass-forming alloys or
metallic glasses formed of Zr--Cu--Al comprising Pd with
compositions according to the formula
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bPd.sub.c are presented in Table
2. In these alloys, the atomic percent of Zr varies from 53 to 65,
the atomic percent of Cu varies from 18 to 35, and the atomic
percent of Pd varies from 0.5 to 7. Thermal and mechanical
properties for the specific embodiments are summarized in Table
2.
TABLE-US-00002 TABLE 2 Sample metallic glasses demonstrating the
effect of increasing Pd atomic concentration by substitution of Cu
according to the formula Zr.sub.(100
-a-b-c)Cu.sub.a-Al.sub.bPd.sub.c Example Composition T.sub.g
(.degree. C.) .DELTA.T.sub.x(.degree. C.) HV 9
Zr.sub.53Cu.sub.35Al.sub.10Pd.sub.2 414 74 497 10
Zr.sub.55Cu.sub.33Al.sub.10Pd.sub.2 410 70 493 11
Zr.sub.55Cu.sub.24.5Al.sub.10Co.sub.1Pd.sub.3 396 88 493 12
Zr.sub.60Cu.sub.24.5Al.sub.10Co.sub.5Pd.sub.0.5 391 92 460 13
Zr.sub.65Cu.sub.19.5Al.sub.10Co.sub.5Pd.sub.0.5 372 89 424 14
Zr.sub.57Cu.sub.30Al.sub.10Pd.sub.3 395 78 480 .+-. 7 15
Zr.sub.59Cu.sub.28Al.sub.10Pd.sub.3 400 66 499 .+-. 7 16
Zr.sub.60Cu.sub.27Al.sub.10Pd.sub.3 392 73 473 .+-. 7 17
Zr.sub.60Cu.sub.25Al.sub.10Pd.sub.5 397 56 494 .+-. 8 18
Zr.sub.60Cu.sub.23Al.sub.10Pd.sub.7 396 55 497 .+-. 4 19
Zr.sub.65Cu.sub.22Al.sub.10Pd.sub.3 374 48 450 .+-. 12 20
Zr.sub.65Cu.sub.20Al.sub.10Pd.sub.5 378 39 443 .+-. 2 21
Zr.sub.65Cu.sub.18Al.sub.10Pd.sub.7 397 24 467 .+-. 9
Description of Co Bearing Ni-Free Zr--Cu--Al Alloys and Metallic
Glass Compositions
[0113] In some embodiments, the disclosure is directed to nickel
free Zr--Cu--Al metallic glass-forming alloys and metallic glasses
that also bear Co. The disclosure is directed to metallic
glass-forming alloys and metallic glasses having a composition
represented by the following formula (subscripts denote atomic
percentages):
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bCo.sub.c
where: a ranges from 18 to 38; b ranges from 8 to 12; c ranges from
2 to 7; and wherein the Zr atomic fraction ranges from 50 to
70.
[0114] In some embodiments, the critical rod diameter of the alloy
is at least 1 mm. In another embodiment of the metallic
glass-forming alloy or metallic glass, the atomic percent of Zr
ranges from 50 to 55. In another embodiment of the metallic
glass-forming alloy or metallic glass, the atomic percent of Zr
ranges from 57 to 65.
[0115] In some embodiments of the metallic glass-forming alloy or
metallic glass, a ranges from 19.5 to 40. In another embodiment of
the metallic glass-forming alloy or metallic glass, a ranges from
18 to 30. In another embodiment of the metallic glass-forming alloy
or metallic glass, a ranges from 33 to 40.
[0116] In some embodiments of the metallic glass-forming alloy or
metallic glass, c ranges from 0.5 to 7. In another embodiment of
the metallic glass-forming alloy or metallic glass, c ranges from 1
to 2. In another embodiment of the metallic glass-forming alloy or
metallic glass, c ranges from 3 to 7.
[0117] In some embodiments, the metallic glass-forming alloy or
metallic glass has a thermal stability of the supercooled liquid
.DELTA.Tx that is at least 77.degree. C.
[0118] In some embodiments, the metallic glass-forming alloy or
metallic glass has a hardness of at least 400 HV. While, in other
embodiments, the metallic glass-forming alloy or metallic glass has
a hardness of at least 425 HV, while in yet other embodiments the
metallic glass-forming alloy or metallic glass has a hardness of at
least 475HV.
[0119] Specific embodiments of metallic glass-forming alloys or
metallic glasses formed of Zr--Cu--Al comprising Cu with
compositions according to the formula
Zr.sub.(100-a-b-c)Cu.sub.aAl.sub.bPd.sub.c are presented in Table
3. In these alloys, the atomic percent of Zr varies from 50 to 65,
the atomic percent of Cu varies from 18 to 38, and the atomic
percent of Co varies from 1 to 7. Thermal and mechanical properties
for the specific embodiments are summarized in Table 3.
TABLE-US-00003 TABLE 3 Sample metallic glasses demonstrating the
effect of increasing Co atomic concentration by substitution of Cu
according to the formula Zr.sub.(100
-a-b-c)Cu.sub.a-Al.sub.bPd.sub.c Example Composition T.sub.g
(.degree. C.) .DELTA.T.sub.x (.degree. C.) HV 22
Zr.sub.50Cu.sub.38Al.sub.10Co.sub.2 418 90 513 23
Zr.sub.53Cu.sub.35Al.sub.10Co.sub.2 418 77 494 24
Zr.sub.55Cu.sub.35Al.sub.10Co.sub.2 401 81 486 25
Zr.sub.55Cu.sub.33Al.sub.10Co.sub.1Pd.sub.1 396 88 493 26
Zr.sub.57Cu.sub.30Al.sub.10Co3 397 80 477 27
Zr.sub.57Cu.sub.28Al.sub.10Co.sub.5 394 86 472 28
Zr.sub.60Cu.sub.27Al.sub.10Co.sub.3 383 90 459 29
Zr.sub.60Cu.sub.25Al.sub.10Co.sub.5 383 96 456 30
Zr.sub.60Cu.sub.23Al.sub.10Co.sub.5Pd.sub.0.5 391 92 460 31
Zr.sub.65Cu.sub.22Al.sub.10Co.sub.3 371 94 435 32
Zr.sub.65Cu.sub.20Al.sub.10Co.sub.5 372 85 433 33
Zr.sub.65Cu.sub.18Al.sub.10Co.sub.7 370 77 434 34
Zr.sub.65Cu.sub.19.5Al.sub.10Co.sub.5Pd.sub.0.5 372 89 424
[0120] From a cosmetic viewpoint of colored oxide layer formation
on Ni-free Zr-based metallic glass-forming alloys or metallic
glasses, tough and uniform oxide layer formation helps to control
color. The color of the oxide surface of the metallic glass surface
can be affected by alloy composition. The texture of the metallic
glass surface can also be affected by alloy composition. For
example, small additives of Pt, Pd, and/or Co can support to
stabilize the oxide layer forming and can provide protection of ion
release under corrosion environment
[0121] Furthermore, the metallic glass-forming alloys and metallic
glasses in accordance with embodiments described above
characterized by the molar ratio of Zr/Cu from 1.1 to 1.6 tends to
show the black color surface by oxidization annealing at Tg-15 in
air-atmosphere.
[0122] The metallic glass-forming alloys and metallic glasses in
accordance with embodiments can be used for black coloring by
simple blasting and oxidizing in Air at Tg-15K. The blasting and
oxidizing method can control the color and texture of the oxidized
metallic glass surface. Uniform surfaces (i.e., without surface
features) and dark (e.g., black) colored surfaces can be achieved
by the combination of blasting and oxidization steps. Tables 4-6
summarize the parameters of L*a*b* space color after black coloring
of embodiments of Ni-free Zr based metallic glass-forming alloys
and metallic glasses described above, by changing of black coloring
condition. Standard methods can be used to evaluate cosmetic
appeal, including color, gloss, and haze. The color of objects may
be determined by the wavelength of light that is reflected or
transmitted without being absorbed, assuming incident light is
white light. The visual appearance of objects may vary with light
reflection or transmission. Additional appearance attributes may be
based on the directional brightness distribution of reflected light
or transmitted light, commonly referred to glossy, shiny, dull,
clear, and haze, among others. The quantitative evaluation may be
performed based on ASTM Standards on Color & Appearance
Measurement, ASTM E-430 Standard Test Methods for Measurement of
Gloss of High-Gloss Surfaces, including ASTM D523 (Gloss), ASTM
D2457 (Gloss on plastics), ASTM E430 (Gloss on high-gloss surfaces,
haze), and ASTM D5767 (DOI), among others. The measurements of
gloss, haze, and DOI may be performed by testing equipment, such as
Rhopoint IQ.
[0123] The metallic glasses can be treated by blasting-oxidizing
(BO), and blasting-oxidizing-blasting (BOB) to control the L*, a*,
and b* values. In particular, the BO and BOB control the black
color. The BOB controls the blueish black color (i.e. b*<0) to
be real black (i.e. B* is approximately zero). The initial blast
can use zirconia fine media (diameter less than about 100 .mu.m)
with high blasting pressure and the final blast can be gentle with
same media.
[0124] In various embodiments, the L*, a*, and/or b* color values
can be controlled in accordance with the embodiments of the
disclosure. For instance, the a* values can be less than or equal
to 1, alternatively less than or equal to 0.75, alternatively less
than or equal to 0.5, or alternatively less than or equal to 0.3.
In other embodiments, the a* values can be greater than or equal to
-1, alternatively be less than or equal to -0.75, alternatively
greater than or equal to -0.5, or alternatively greater than or
equal to -0.3.
[0125] Further, the b* values can be less than or equal to 5, less
than or equal to 4, less than or equal to 3, less than or equal to
1, less than or equal to 0.50. Further, the b* values can be
greater than or equal to -5, greater than or equal to -4, greater
than or equal -3, greater than or equal to + or -1, greater than or
equal to + or -0.50.
[0126] In various aspects, the L* value can be less than or equal
to 50. Alternatively, the L* value can be less than or equal to 45.
Alternatively, the L* value can be less than or equal to 40.
Alternatively, the L* value can be less than or equal to 35.
Alternatively, the L* value can be greater than or equal to 30.
Alternatively, the L* value can be greater than or equal to 35.
Alternatively, the L* value can be greater than or equal to 40.
Alternatively, the L* value can be greater than or equal to 45.
[0127] As mentioned above, the addition of the minor elements of
Pd, Pt, and/or Co can also increase corrosion resistance. The
corrosion resistance of example alloy compositions in accordance
with embodiments as described were evaluated by a salt-mist spray
corrosion test (ASTM B117) for 24 hours. ATSM B117 is a
standardized test for checking corrosion resistance of materials
and surface coatings. Results of the corrosion testing are reported
as a rating letter for a period of time (e.g., 24 hours). Tables 7
and 8 show the corrosion ratings for sample alloy compositions in
accordance with embodiments of the disclosure. As shown in the
tables, some of samples alloy compositions containing Pt have
improved corrosion resistance. Also, samples of alloy compositions
containing Co and Pd show enhanced corrosion resistance in
comparison to the ternary Zr--Cu--Al BMGs systems.
[0128] In order to realize the mechanism of corrosion resistance,
the micro-structure of the black-colored (oxidized) Ni-free
Zr-based BMGs was observed. The surface region of the black colored
Zr.sub.57Cu.sub.31Al.sub.10Pt.sub.2 alloys was mapped using EDX.
The noteworthy point, the distribution of Pt element is quite
uniform even in the oxide layer. In contrast, Cu and Al are
segregated at the interfaces in oxide layer, even though the
distribution of Cu and Al is homogeneous in BMG matrix. As
concluded, the quite uniform distribution of 4.sup.th element of Pt
even in oxide layer is one of reason to increase the corrosion
resistance.
TABLE-US-00004 TABLE 7 Sample metallic glasses demonstrating the
corrosion resistance effect of increasing Pt and Pd atomic
concentration by substitution of Cu according to the formula
Zr.sub.(100 -a-b-c)Cu.sub.a-Al.sub.bPd.sub.c on the L*a*b* space
color Corrosion Rating for Example Composition ASTM B117 Oxidation
Method Zr.sub.57Cu.sub.30Al.sub.10Pd.sub.3 d
Zr.sub.57Cu.sub.30Al.sub.10Pt.sub.3 b BO
Zr.sub.59Cu.sub.28Al.sub.10Pd.sub.3 d
Zr.sub.60Cu.sub.27Al.sub.10Pd.sub.3 d
Zr.sub.60Cu.sub.25Al.sub.10Pd.sub.5 d
Zr.sub.60Cu.sub.23Al.sub.10Pd.sub.7 d BOB
Zr.sub.60Cu.sub.27Al.sub.10Pt.sub.3 b
TABLE-US-00005 TABLE 8 Sample metallic glasses demonstrating the
corrosion resistance effect of increasing Pt and Pd atomic
concentration by substitution of Cu according to the formula
Zr.sub.(100 -a-b-c)Cu.sub.a-Al.sub.bPd.sub.c on the L*a*b* space
color Corrosion Rating for Example Composition ASTM B117 Oxidation
Method Zr.sub.60Cu.sub.25Al.sub.10Pt.sub.5 c BO
Zr.sub.60Cu.sub.23Al.sub.10Pt.sub.7 b BO
Zr.sub.65Cu.sub.22Al.sub.10Pd.sub.3 c BOB
Zr.sub.65Cu.sub.20Al.sub.10Pd.sub.5 d BOB
Zr.sub.65Cu.sub.13Al.sub.10Pd.sub.7 d
Zr.sub.65Cu.sub.22Al.sub.10Pt.sub.3 b BO
Zr.sub.65Cu.sub.20Al.sub.10Pt.sub.5 b
Zr.sub.50Cu.sub.18Al.sub.10Pt.sub.7 b
[0129] In order to understand the mechanism contributing to the
enhancement of corrosion resistance, the micro-structure of the
black-colored (oxidized) Ni-free Zr-based samples of the alloy
composition Zr.sub.57Cu.sub.31Al.sub.10Pt.sub.2 was examined using
EDX mapping of surface region. From the EDX mapping it was observed
that the distribution of the Pt minor element was substantially
uniformly distributed in the oxide layer. In contrast, it was
observed that the Cu and Al elements were segregated at the
interfaces in oxide layer, even though the distribution of Cu and
Al is homogeneous in BMG matrix. Thus, without wishing to be held
to a specific mechanism or mode of action, it appears that the
uniform distribution of the minor element (Pt, Pd, and/or Co) in
the oxide layer contributes to the enhanced corrosion
resistance.
[0130] The alloys described herein can be valuable in the
fabrication of electronic devices using a metallic glass-containing
part. An electronic device herein can refer to any electronic
device known in the art. For example, it can be a telephone, such
as a mobile phone, and a land-line phone, or any communication
device, such as a smart phone, including, for example an
iPhone.RTM., and an electronic email sending/receiving device. It
can be a part of a display, such as a digital display, a TV
monitor, an electronic-book reader, a portable web-browser (e.g.,
iPad.RTM.), and a computer monitor. It can also be an entertainment
device, including a portable DVD player, conventional DVD player,
Blue-Ray disk player, video game console, music player, such as a
portable music player (e.g., iPod.RTM.), etc. It can also be a part
of a device that provides control, such as controlling the
streaming of images, videos, sounds (e.g., Apple TV.RTM.), or it
can be a remote control for an electronic device. It can be a part
of a computer or its accessories, such as the hard drive tower
housing or casing, laptop housing, laptop keyboard, laptop track
pad, desktop keyboard, mouse, and speaker. The article can also be
applied to a device such as a watch or a clock.
[0131] The foregoing description, for purposes of explanation, used
specific nomenclature to provide a thorough understanding of the
described embodiments. However, it will be apparent to one skilled
in the art that the specific details are not required in order to
practice the described embodiments. Thus, the foregoing
descriptions of the specific embodiments described herein are
presented for purposes of illustration and description. They are
not target to be exhaustive or to limit the embodiments to the
precise forms disclosed. It will be apparent to one of ordinary
skill in the art that many modifications and variations are
possible in view of the above teachings.
* * * * *