U.S. patent application number 10/750755 was filed with the patent office on 2004-07-15 for titanium alloys having improved castability.
This patent application is currently assigned to CANA LAB CORPORATION. Invention is credited to Cheng, Wen-Wei, Chern Lin, Jiin-Huey, Ju, Chien-Ping, Lee, Chih-Min, Lin, Dan Jae.
Application Number | 20040136859 10/750755 |
Document ID | / |
Family ID | 46300645 |
Filed Date | 2004-07-15 |
United States Patent
Application |
20040136859 |
Kind Code |
A1 |
Chern Lin, Jiin-Huey ; et
al. |
July 15, 2004 |
Titanium alloys having improved castability
Abstract
In order to improve castability of a titanium alloy, 0.01-5 wt
%, preferably 0.1-3 wt %, of bismuth is introduced into the
titanium alloy, based on the weight of bismuth and the titanium
alloy. The titanium alloy is suitable for making a dental casting
or a medical implant by casting.
Inventors: |
Chern Lin, Jiin-Huey;
(Winnetka, IL) ; Ju, Chien-Ping; (Carbondale,
IL) ; Cheng, Wen-Wei; (Miaoli, TW) ; Lin, Dan
Jae; (Taipei, TW) ; Lee, Chih-Min; (Kaohsiung,
TW) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA
VA
22314
|
Assignee: |
CANA LAB CORPORATION
TAIPEI
TW
|
Family ID: |
46300645 |
Appl. No.: |
10/750755 |
Filed: |
January 5, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10750755 |
Jan 5, 2004 |
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10179310 |
Jun 26, 2002 |
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10179310 |
Jun 26, 2002 |
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09548266 |
Apr 12, 2000 |
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6572815 |
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Current U.S.
Class: |
420/417 ;
420/418; 420/421 |
Current CPC
Class: |
C22C 14/00 20130101 |
Class at
Publication: |
420/417 ;
420/418; 420/421 |
International
Class: |
C22C 014/00 |
Claims
What is claimed is:
1. A medical device made of a biocompatible titanium alloy
composition having an improved castability comprising: (a) about
0.01-5 wt % Bi based on the weight of the alloy composition; (b) at
least one alloy element selected from the group consisting of Mo,
Nb, Ta, Zr and Hf; and (c) the balance Ti.
2. The medical device as set forth in claim 1, wherein said alloy
composition comprises 0.1-3 wt % Bi.
3. The medical device as set forth in claim 1, wherein said alloy
composition further comprises at least one eutectoid beta
stabilizing element selected from the group consisting of Fe, Cr,
Mn, Co, Ni, Cu, Ag, Au, Pd, Si and Sn.
4. The medical device as set forth in claim 1, wherein said
titanium alloy composition is substantially free from V.
5. The medical device as set forth in claim 1, wherein the titanium
alloy composition is substantially free from Al.
6. The medical device as set forth in claim 2, wherein the titanium
alloy composition consists essentially of Ti and Mo; Ti and Nb; Ti
and Zr; Ti, Mo and Fe; Ti, Mo and Cr; Ti, Mo and Nb; Ti, Mo and Ta;
Ti, Nb and Fe; Ti, Ta and Fe; Ti, Nb and Zr; Ti, Al and Nb; Ti, Mo,
Zr and Fe; or Ti, Mo, Hf and Fe, in addition to Bi.
7. The medical device as set forth in claim 1 which is a dental
casting.
8. The medical device as set forth in claim 1 which is a medical
implant.
9. A method for improving a castability of a titanium alloy
comprising at least one alloy element selected from the group
consisting of Mo, Nb, Ta, Zr and Hf, said method comprising
introducing about 0.01-5 wt % Bi into said titanium alloy, based on
the weight of Bi and said titanium alloy.
10. The method as set forth in claim 9, wherein 0.1-3 wt % Bi is
introduced into said titanium alloy.
11. The method as set forth in claim 9, wherein said titanium alloy
further comprises at least one eutectoid beta stabilizing element
selected from the group consisting of Fe, Cr, Mn, Co, Ni, Cu, Ag,
Au, Pd, Si and Sn.
12. The method as set forth in claim 9, wherein the titanium alloy
is substantially free from V.
13. The method as set forth in claim 9, wherein the titanium alloy
is substantially free from Al.
14. The method as set forth in claim 10, wherein said titanium
alloy consists essentially of Ti and Mo; Ti and Nb; Ti and Zr; Ti,
Mo and Fe; Ti, Mo and Cr; Ti, Mo and Nb; Ti, Mo and Ta; Ti, Nb and
Fe; Ti, Ta and Fe; Ti, Nb and Zr; Ti, Al and Nb; Ti, Mo, Zr and Fe;
or Ti, Mo, Hf and Fe.
15. A method of using a titanium alloy composition in making a
medical device comprising casting a titanium alloy composition
comprising (a) about 0.01-5 wt % Bi based on the weight of the
alloy composition; (b) at least one alloy element selected from the
group consisting of Mo, Nb, Ta, Zr and Hf; and (c) the balance
Ti.
16. The method as set forth in claim 15, wherein said alloy
composition comprises 0.1-3 wt % Bi.
17. The method as set forth in claim 15, wherein said alloy
composition further comprises at least one eutectoid beta
stabilizing element selected from the group consisting of Fe, Cr,
Mn, Co, Ni, Cu, Ag, Au, Pd, Si and Sn.
18. The method as set forth in claim 15, wherein said titanium
alloy composition is substantially free from V.
19. The method as set forth in claim 15, wherein the titanium alloy
composition is substantially free from Al.
20. The method as set forth in claim 16, wherein the titanium alloy
composition consists essentially of Ti and Mo; Ti and Nb; Ti and
Zr; Ti, Mo and Fe; Ti, Mo and Cr; Ti, Mo and Nb; Ti, Mo and Ta; Ti,
Nb and Fe; Ti, Ta and Fe; Ti, Nb and Zr; Ti, Al and Nb; Ti, Mo, Zr
and Fe; or Ti, Mo, Hf and Fe, in addition to Bi.
21. The method as set forth in claim 15, wherein said medical
device is a dental casting.
22. The method as set forth in claim 15, wherein said medical
device is a medical implant.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation-in-part
application of U.S. patent application Ser. No. 10/179,310, filed
Jun. 26, 2002, which is a continuation-in-part application of U.S.
patent application Ser. No. 09/548,266, filed Apr. 12, 2000, now
U.S. Pat. No. 6,572,815B 1. The above-listed U.S. Pat. No.
6,572,815B1 and application Ser. No. 10/179,310 are commonly
assigned with the present invention and the entire contents of
which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a titanium alloy, and more
particularly to a titanium alloy casting. The present invention
provides a method to improve the castability of a titanium alloy,
so that it is more suitable for use in making a dental casting and
a medical implant.
BACKGROUND OF THE INVENTION
[0003] Due to its lightweight, high strength-to-weight ratio, low
elastic modulus, superior chemical corrosion resistance, and
excellent mechanical properties at high temperature up to
550.degree. C., titanium and its alloys have been widely used on
aerospace, chemical, sports, and marine industries. Their superior
biocompatibility also makes them ideal as the primary materials
used in dental and osteological restorations or implants, such as
artificial bone pins, bone plates, shoulders, elbows, hips, knees
and other joints, and dental orthopraxy lines.
[0004] A number of methods for fabricating titanium and its alloys
with a desired shape have been developed. Among these, precision
casting is the most difficult. Precision casting has the advantage
that the cast produced has a near net shape, which greatly
decreases the titanium fabrication cost. Also, precision casting is
particularly suitable for producing objects with a small volume,
high size accuracy, and complicated shape, for example in dental
and osteological fields. Moreover, titanium and its alloys could
even be utilized in many other everyday products, if the difficulty
in precision casting could be solved.
[0005] There are many factors that affect the process of the
precision casting and the properties of castings. According to the
research results issued by Luk et al., in Dent. Mater., 8, 89-99,
1992, the factors include alloy composition, alloy density, alloy
surface tension, casting temperature, investment material type,
mold temperature, casting machine type, casting surface area/volume
ratio, and pouring angle. The castability test is the most
frequently used method for assessing various titanium precision
casting processes. Castability is the ability of a molten alloy to
completely fill a mold space. Castability is a combination factor,
and there is no international standard for assessing it today.
Since castability is affected by many factors, researchers have
designed various test methods in accordance with various cast
patterns for assessing the castability. The cast patterns include
spiral wax molds, fibrous nylon lines produced by injection molding
(Howard et al., JDR, 59, 824-830, 1985), saucer-like molds,
cylindrical molds, rectangle sheets, nylon mesh, and taper molds
(Mueller et al., J. of Prosth. Den., 69, 367, Abstr. 2072, 1993). A
wax mold of a simulated crown has also been designed (Bessing et
al., Acta Odontology Scandinavian, 44, 165-172, 1986).
[0006] Titanium is inherently difficult to cast due to its high
melting point and high reactivity. Its low density is another
problem in casting. Therefore, the improvement of casting process
is the main issue of titanium precision casting. The casting
machines used at present utilize argon as the protective atmosphere
to prevent high temperature reactions. Induction or arc is used as
the heat source in order to shorten melting time as well as lessen
high temperature reactivity. At present, in order to increase the
pouring force and to avoid casting defect caused by poor
flowability of the molten metal, the titanium casting machines can
be roughly divided into the centrifugal casting type, the
vacuum-pressure type, and the centrifugal-vacuum pressure mixed
type (Yoshiaki, Conference Paper, 1-7, Australia, 1995).
[0007] U.S. Pat. No. 6,572,815B1 discloses a technique to improve
the castability of pure titanium by doping an alloying metal in an
amount of 0.01 to 3 wt %, preferably 0.5 to 3 wt %, and more
preferably about 1 wt %. Among various alloying metals used in this
application bismuth is found the most promising element.
[0008] U.S. Pat. No. 2,797,996 discloses titanium base alloys of
high strength and ductility, and also of contamination resistance
and high strength at elevated temperatures, which contain as
essentially constituents titanium and tin, together with one or
more additional metals selected from the groups comprising alpha
promoters, beta promoters and compound formers. A large number of
Ti--Sn base alloys were prepared in this patent, including ternary
titanium alloys containing 1-5 wt % Bi. However, there is no
teaching as to the improvement of castability or reducing surface
tension of pure titanium or a titanium alloy.
[0009] U.S. Pat. No. 4,810,465 discloses a free-cutting Ti alloy.
The basic alloy composition of this free-cutting Ti alloy
essentially consists of at least one of S: 0.001-10%, Se: 0.001-10%
and Te: 0.001-10%; REM: 0.01-10%; and one or both of Ca: 0.001-10%
and B: 0.005-5%; and the balance substantially Ti. The Ti alloy
includes one or more of Ti--S (Se, Te) compounds, Ca--S (Se, Te)
compounds, REM-S (Se, Te) compounds and their complex compounds as
inclusions to improve machinability. Some optional elements can be
added to above basic composition. Also disclosed are methods of
producing the above free-cutting Ti alloy and a specific Ti alloy
which is a particularly suitable material for connecting rods.
Bismuth up to 10% was suggested in this free-cutting Ti alloy.
However, there is no teaching as to the improvement of castability
or reducing surface tension of pure titanium or a titanium
alloy.
[0010] U.S. Pat. No. 5,176,762 discloses an age hardenable beta
titanium alloy having exceptional high temperature strength
properties in combination with an essential lack of combustibility.
In its basic form the alloy contains chromium, vanadium and
titanium the nominal composition of the basic alloy being defined
by three points on the ternary titanium-vanadium-chromium phase
diagram: Ti-22V-13Cr, Ti-22V-36Cr, and Ti-40V-13% Cr. The alloys of
the invention are comprised of the beta phase under all the
temperature conditions, have strengths much in excess of the prior
art high strength alloys in combination with excellent creep
properties, and are nonburning under conditions encountered in gas
turbine engine compressor sections. Bismuth up to 1.5% was
suggested in this age hardenable beta titanium alloy. However,
there is no teaching as to the improvement of castability or
reducing surface tension of pure titanium or a titanium alloy.
SUMMARY OF THE INVENTION
[0011] A primary object of the present invention is to provide a
medical device made of a titanium alloy having an improved
castability.
[0012] Another object of the present invention is to provide a
method of improving a castability of a titanium alloy.
[0013] A further object of the present invention is to provide a
method of using a titanium alloy in making a medical device.
[0014] The present invention discloses a method for improving a
castability of a titanium alloy comprising at least one alloy
element selected from the group consisting of Mo, Nb, Ta, Zr and
Hf, said method comprising introducing about 0.01-5 wt % Bi into
said titanium alloy, preferably 0.1-3 wt % Bi, based on the weight
of Bi and said titanium alloy.
[0015] Preferably, said titanium alloy further comprises at least
one eutectoid beta stabilizing element selected from the group
consisting of Fe, Cr, Mn, Co, Ni, Cu, Ag, Au, Pd, Si and Sn.
[0016] Preferably, the titanium alloy is substantially free from
V.
[0017] Preferably, the titanium alloy is substantially free from
Al.
[0018] Preferably, said titanium alloy consists essentially of Ti
and Mo; Ti and Nb; Ti and Zr; Ti, Mo and Fe; Ti, Mo and Cr; Ti, Mo
and Nb; Ti, Mo and Ta; Ti, Nb and Fe; Ti, Ta and Fe; Ti, Nb and Zr;
Ti, Al and Nb; Ti, Mo, Zr and Fe; or Ti, Mo, Hf and Fe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will be described in detail with
reference to the illustrated embodiments and the accompany
drawings, in which:
[0020] FIG. 1 is a schematic drawing showing the copper mold used
for the castability test in the present invention;
[0021] FIG. 2 shows the effect on castability by doping 1 wt %, 3
wt % and 5 wt % of bismuth to commercially pure titanium (c.p. Ti)
and a Ti alloy containing 7.5 wt % Mo and the balance Ti (Ti-7.5Mo)
according to the present invention;
[0022] FIG. 3 shows the effect on castability by doping 1 wt %, 3
wt % and 5 wt % of bismuth to a Ti alloy containing 6 wt % Al, 4 wt
% V and the balance Ti (Ti6Al4V) according to the present
invention; and
[0023] FIG. 4 shows the effect on castability by doping 1 wt % of
bismuth to various titanium alloys according to the present
invention, wherein the numerals before the elements in the Ti
alloys represent the weight percentage thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention provides a medical device made of a
biocompatible titanium alloy composition having an improved
castability comprising:
[0025] (a) about 0.01-5 wt % Bi, preferably 0.1-3 wt % Bi, based on
the weight of the alloy composition;
[0026] (b) at least one alloy element selected from the group
consisting of Mo, Nb, Ta, Zr and Hf; and
[0027] (c) the balance Ti.
[0028] The present invention also provides a method of using a
titanium alloy composition in making a medical device comprising
casting the above-mentioned biocompatible titanium alloy
composition.
[0029] Preferably, said alloy composition further comprises at
least one eutectoid beta stabilizing element selected from the
group consisting of Fe, Cr, Mn, Co, Ni, Cu, Ag, Au, Pd, Si and
Sn.
[0030] Preferably, said titanium alloy composition is substantially
free from V.
[0031] Preferably, the titanium alloy composition is substantially
free from Al.
[0032] Preferably, the titanium alloy composition consists
essentially of Ti and Mo; Ti and Nb; Ti and Zr; Ti, Mo and Fe; Ti,
Mo and Cr; Ti, Mo and Nb; Ti, Mo and Ta; Ti, Nb and Fe; Ti, Ta and
Fe; Ti, Nb and Zr; Ti, Al and Nb; Ti, Mo, Zr and Fe; or Ti, Mo, Hf
and Fe, in addition to Bi.
[0033] Preferably, the medical device is a dental casting.
[0034] Preferably, the medical device is a medical implant.
EXAMPLE 1
c.p. Ti and Ti--Mo alloys doped with 1 wt %, 3 wt % and 5 wt % of
Bi
[0035] In this example 0, 1, 3 and 5 wt % of bismuth of 99.5% in
purity were melted into a grade II commercially pure titanium (c.p.
Ti) and Ti-7.5Mo alloy containing 7.5 wt % of Mo and the balance Ti
by using a commercial arc-melting vacuum/pressure type casting
system (Castmatic, Iwatani Corp., Japan). Appropriate amounts of
c.p. Ti, molybdenum and bismuth were melted in a U-shaped copper
hearth with a tungsten electrode. The melting chamber was first
evacuated and purged with argon. An argon pressure of 1.8
kgf/cm.sup.2 was maintained during melting. After
solidification/cooling in the same chamber in argon atmosphere, the
thin oxidized layer of the ingot was removed by grinding and the
ground surface was ultrasonically cleaned in alcohol. The ingot was
re-melted three times to improve chemical homogeneity.
[0036] Prior to casting, the ingot was re-melted again in an
open-based copper hearth under an argon pressure of 1.8
kgf/cm.sup.2. The molten alloy instantly dropped from the
open-based copper hearth into a copper mold located in a second
chamber at room temperature via a pouring gate because of the
pressure difference between the two chambers. As shown in FIG. 1,
the pouring gate 20 has an inlet of 20 mm diameter and an outlet of
10 mm diameter, and a thickness of 18 mm between the inlet and the
outlet. The copper mold 10 has two parallel needle-shaped cavities
of 1 mm.times.53 mm (diameter.times.length).
[0037] Cast lengths (a measure of castability) of undoped and
Bi-doped c.p. Ti as well as Ti-7.5Mo alloy are compared in FIG. 2.
As shown in the figure, when 1 or 3 wt % Bi was doped in c.p. Ti,
the cast length increased by about 12%. When 5 wt % Bi was added,
however, the castability value declined. This "up and down"
phenomenon was observed in a more dramatic way in Ti-7.5Mo system.
When 1 wt % Bi was doped in Ti-7.5Mo alloy, the cast length largely
increased by 34%. Again, when larger amounts of bismuth were added,
the castability values decreased.
[0038] According to the theory of Ragone et al. [RAGONE, D. V.
ADAMS, C. M., and TAYLOR, H. F. (1956) Some Factors Affecting
Fluidity of Metals. AFS Trans., 64, 640.], addition of an alloy
element to a pure metal always lowers the fluidity (increasing
viscosity) of the metal due to the formation of dendrites that
causes resistance to fluid flow at the early stage of
solidification. This factor might satisfactorily explain why the
castability value decreased when a relatively large amount (3 or 5
wt %) of bismuth was added. However, the dendrite factor could not
explain the increase in castability when only 1 wt % Bi was
added.
EXAMPLE 2
Ti6Al4V Alloy Doped with 1 wt %, 3 wt % and 5 wt % of Bi
[0039] The procedures in Example 1 were repeated except that a
commercially available Ti-6Al-4V alloy (Titanium Industries,
Parsippany, N.J., USA) was used to replace c.p. Ti and Mo metals.
The results are shown in FIG. 3.
[0040] From the measurement of casting lengths (a measure of
castability, FIG. 3), it is interesting to note that the
castability of Ti-6Al-4V alloy could be largely enhanced by almost
30% by the addition of 1 wt % Bi in the alloy, compared to that of
undoped one. When a larger amount (3 or 5 wt %) of bismuth was
added, however, the castability value of Ti-6Al-4V was not
improved.
EXAMPLE 3
Castability of Some Commercial Ti Alloys with 1 wt % Bi Doped and
without Bi Doped
[0041] The procedures for preparing the doped and undoped Ti-7.5Mo
alloys in Example 1 were repeated to prepare Ti7.5Mo--Fe alloys
with 1 wt % Bi doped and without Bi doped except that an additional
metal Fe was added in an amount of 1, 3 and 5 wt %, separately.
[0042] The procedures for preparing the doped and undoped Ti-7.5Mo
alloys in Example 1 were repeated to prepare Ti15Mo alloy with 1 wt
% Bi doped and without Bi doped except that the amount of Mo added
was 15 wt %.
[0043] The procedures in Example 1 were repeated except that
commercially available alloys TMZF (12 wt % of Mo, 6 wt % of Zr, 2
wt % of Fe, and the balance Ti) (Titanium Industries, Parsippany,
N.J., USA), Ti13Nb13Zr (13 wt % of Nb, 13 wt % of Zr and the
balance Ti) (Titanium Industries, Parsippany, N.J., USA),
Ti5Al2.5Fe (5 wt % of Al, 2.5 wt % of Fe and the balance Ti)
(Titanium Industries, Parsippany, N.J., USA), Ti6Al7Nb (6 wt % of
Al, 7 wt % of Nb and the balance Ti) (Titanium Industries,
Parsippany, N.J., USA), and Ti7Mo7Hf1Fe (7 wt % of Mo, 7 wt % of
Hf, 1 wt % of Fe and the balance Ti) (Titanium Industries,
Parsippany, N.J., USA) were used to replace c.p. Ti and Mo metals.
The results are shown in FIG. 4 together with the 1 wt % Bi doped
and undoped c.p. Ti, Ti7.5Mo, Ti6Al4V alloys prepared in Examples 1
and 2.
[0044] From the measurement of casting lengths (a measure of
castability, FIG. 4), it can be seen that the castability of Ti
alloys enhanced by the addition of 1 wt % Bi in the alloy ranges
from about 17% (Ti5Al2.5Fe) to about 115% (Ti7.5Mo5Fe), compared to
that of undoped one, while the castability improvement for c.p. Ti
by the addition of 1 wt % Bi is only about 12%.
[0045] More examples of titanium alloys were prepared and the
castability thereof was evaluated following the procedures recited
in Example 1. The results are show in the following Table 1
together with those of the alloys prepared in Examples 1 and 3.
1TABLE 1 Improvement in castability (cast length) of Ti alloys due
to the presence of Bi Ti alloy Cast length Improvement in
composition (wt %) (mm) cast length (%) Ti--7.5Mo 11.5 --
Ti--7.5Mo--1Bi 15.4 33.9 Ti--7.5Mo--3Bi 13.6 18.3 Ti--7.5Mo--5Bi
12.0 4.3 Ti--7.5Mo--1Fe 7.3 -- Ti--7.5Mo--1Fe--1Bi 13.1 79.5
Ti--7.5Mo--2Fe 8.3 -- Ti--7.5Mo--2Fe--0.1Bi 11.1 33.7
Ti--7.5Mo--2Fe--0.5Bi 12.7 53.0 Ti--7.5Mo--2Fe--1Bi 13.5 62.7
Ti--7.5Mo--3Fe 6.9 -- Ti--7.5Mo--3Fe--1Bi 12.6 82.6 Ti--7.5Mo--5Fe
6.8 -- Ti--7.5Mo--5Fe--1Bi 14.5 113.2 Ti--7.5Mo--2Cr 12.5 --
Ti--7.5Mo--2Cr--1Bi 13.7 9.6 Ti--15Mo 12.7 -- Ti--15Mo--1Bi 16.2
27.6 Ti--15Mo--3Bi 14.8 16.5 Ti--15Mo--5Nb 12.9 --
Ti--15Mo--5Nb--1Bi 15.4 19.4 Ti--15Mo--5Ta 12.0 --
Ti--15Mo--5Ta--1Bi 13.0 8.3 Ti--15Mo--2Fe 8.2 -- Ti--15Mo--2Fe--1Bi
9.8 19.5 Ti--15Mo--2Cr 12.3 -- Ti--15Mo--2Cr--1Bi 16.7 35.8
Ti--20Mo 12.6 -- Ti--20Mo--1Bi 15.7 24.6 Ti--10Nb 10.8 --
Ti--10Nb--1Bi 18.5 71.3 Ti--25Nb 10.5 -- Ti--25Nb--1Bi 14.7 40.0
Ti--25Nb--2Fe 7.0 -- Ti--25Nb--2Fe--1Bi 9.2 31.4 Ti--25Ta--2Fe 7.2
-- Ti--25Ta--2Fe--1Bi 8.4 16.7 Ti--35Nb 8.0 -- Ti--35Nb--1Bi 11.2
40.0 Ti--12Mo--6Zr--2Fe 9.2 -- Ti--12Mo--6Zr--2Fe--1Bi 11.1 20.7
Ti--13Nb--13Zr 9.2 -- Ti--13Nb--13Zr--1Bi 14.5 57.6 Ti--5Al--2.5Fe
10.8 -- Ti--5Al--2.5Fe--1Bi 12.6 16.7 Ti--6Al--7Nb 14.1 --
Ti--6Al--7Nb--1Bi 17.2 22.0 Ti--7Mo--7Hf--1Fe 8.0 --
Ti--7Mo--7Hf--1Fe--1Bi 10.5 31.2 Ti--30Zr 13.2 -- Ti--30Zr--1Bi
14.1 6.7
* * * * *