U.S. patent application number 13/701159 was filed with the patent office on 2013-03-21 for titanium alloy complex powder containing copper powder, chromium powder or iron powder, titanium alloy material consisting of this powder, and process for production thereof.
The applicant listed for this patent is Osamu Kano, Satoshi Sugawara, Hideo Takatori. Invention is credited to Osamu Kano, Satoshi Sugawara, Hideo Takatori.
Application Number | 20130071284 13/701159 |
Document ID | / |
Family ID | 45066907 |
Filed Date | 2013-03-21 |
United States Patent
Application |
20130071284 |
Kind Code |
A1 |
Kano; Osamu ; et
al. |
March 21, 2013 |
TITANIUM ALLOY COMPLEX POWDER CONTAINING COPPER POWDER, CHROMIUM
POWDER OR IRON POWDER, TITANIUM ALLOY MATERIAL CONSISTING OF THIS
POWDER, AND PROCESS FOR PRODUCTION THEREOF
Abstract
A process for production of titanium alloy material has steps of
hydrogenating titanium alloy material to generate hydrogenated
titanium alloy; grinding, sifting and dehydrogenating the
hydrogenated titanium alloy powder to generate titanium alloy
powder; adding at least one of copper powder, chromium powder or
iron powder to obtain titanium alloy complex powder; consolidating
the titanium alloy complex powder by CIP process and subsequent HIP
process, or by HIP process after filling the titanium alloy complex
powder into a capsule. In addition, titanium alloy complex powder
and titanium alloy material produced by the process are
provided.
Inventors: |
Kano; Osamu; (Chigasaki-shi,
JP) ; Takatori; Hideo; (Chigasaki-shi, JP) ;
Sugawara; Satoshi; (Chigasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kano; Osamu
Takatori; Hideo
Sugawara; Satoshi |
Chigasaki-shi
Chigasaki-shi
Chigasaki-shi |
|
JP
JP
JP |
|
|
Family ID: |
45066907 |
Appl. No.: |
13/701159 |
Filed: |
May 31, 2011 |
PCT Filed: |
May 31, 2011 |
PCT NO: |
PCT/JP2011/062873 |
371 Date: |
November 30, 2012 |
Current U.S.
Class: |
419/30 ; 75/245;
75/255; 75/343 |
Current CPC
Class: |
B22F 1/0003 20130101;
Y02W 30/50 20150501; C22C 14/00 20130101; Y02W 30/541 20150501;
B22F 9/023 20130101; Y02P 10/24 20151101; Y02P 10/20 20151101; C22C
1/0458 20130101; B22F 2998/10 20130101; B22F 8/00 20130101; B22F
2998/10 20130101; B22F 9/023 20130101; B22F 9/04 20130101; B22F
1/0003 20130101; B22F 3/04 20130101; B22F 3/15 20130101 |
Class at
Publication: |
419/30 ; 75/255;
75/343; 75/245 |
International
Class: |
B22F 1/00 20060101
B22F001/00; C22C 14/00 20060101 C22C014/00; C22C 1/04 20060101
C22C001/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2010 |
JP |
2010-124455 |
Claims
1. Titanium alloy complex powder comprising: titanium alloy powder
containing aluminum and vanadium, or containing at least one kind
selected from zirconium, tin, molybdenum, iron and chromium in
addition to aluminum and vanadium, and at least one kind of
metallic powder selected from copper powder, chromium powder and
iron powder mixed with the titanium alloy powder, wherein the
titanium alloy powder is made from hydrogenating titanium alloy as
a raw material to generate hydrogenated titanium alloy powder and
by dehydrogenating this hydrogenated titanium alloy powder, and
wherein the amount of the metallic powder ranges from 1 to 10 wt %
in case that one metallic powder is added, and the amount of the
metallic powder added ranges from 1 to 20 wt % in case that two or
more metallic powders are mixed.
2. (canceled)
3. The titanium alloy complex powder according to claim 1, wherein
average particle size of the copper powder, chromium powder or iron
powder ranges from 1 to 300 .mu.m.
4. A process for production of titanium alloy complex powder,
comprising steps of: hydrogenating titanium alloy raw material to
generate hydrogenated titanium alloy powder, dehydrogenating the
hydrogenated titanium alloy powder to generate titanium alloy
powder, and mixing at least one of copper powder, chromium powder
or iron powder with the titanium alloy powder.
5. A process for production of titanium alloy material, comprising
steps of: consolidating the titanium alloy complex powder according
to claim 1 by CIP process and subsequent HIP process, or by HIP
process after filling the titanium alloy complex powder into a
capsule.
6. A titanium alloy material produced by the process according to
claim 5.
7. The titanium alloy material according to claim 6, wherein the
density of the titanium alloy material is not less than 99% to the
theoretical one.
8. A process for production of titanium alloy material, comprising
steps of: consolidating the titanium alloy complex powder according
to claim 3 by CIP process and subsequent HIP process, or by HIP
process after filling into a capsule.
9. A titanium alloy material produced by the process according to
claim 8.
10. The titanium alloy material according to claim 9, wherein the
density of the titanium alloy material is not less than 99% of the
theoretical one.
Description
TECHNICAL FIELD
[0001] The present invention relates to titanium alloy complex
powder containing copper powder, chromium powder or iron powder,
titanium alloy material consisting of the powder and a process for
production thereof, and in particular, relates to titanium alloy
material having superior mechanical properties and relates to a
process for production thereof.
BACKGROUND ART
[0002] Titanium alloy, in particular, Ti-6Al-4V alloy has been well
known as a material for airplanes. The titanium alloy is produced
by a vacuum arc remelting method or an electron beam remelting
method. The vacuum arc remelting method is a process in which Al--V
master alloy is added to titanium material at an appropriate
amount, this is pressed into briquettes, the briquettes are
mutually bonded to form an electrode for remelting, the electrode
for remelting is set in the vacuum arc remelting furnace, and the
electrode is remelted in the vacuum to produce alloy ingots.
[0003] On the other hand, the electron beam remelting method is a
process in which material for remelting consisting of titanium
material and Al--V master alloy is supplied to a hearth, an
electron beam is irradiated on the material to remelt it, and the
melted metal is poured into a mold arranged downstream of the
hearth to produce alloy ingots.
[0004] However, in the above-mentioned methods for remelting
titanium alloy, since the ingot is solidified from downward to
upward progressively, there is a problem of component segregation
in which alloy components differ from the lower side to the upper
side of the ingot. Because of the segregation, it is difficult to
add an alloy component or a third addition component at high
concentrations. In addition, in the electron beam remelting method,
there is a problem that a low-melting point component will
evaporate from the hearth and therefore there will be variation of
components in the melted metal over time.
[0005] Unlike the above-mentioned remelting method, since a method
in which alloy powder material mixed uniformly is pressed and
molded is employed, the alloy produced with powder material is
greatly advantageous from the viewpoint of segregation compared to
an alloy produced by the remelting method in which an ingot is
solidified from the lower side to the upper side progressively. In
addition, since the alloy is not produced via a step of being
melted metal, there is no problem of evaporation of a low-melting
point component. In this way, the powder method process for
production of titanium alloy has several advantages compared to the
remelting method.
[0006] However, the titanium alloy powder used in the powder method
has inferior workability and formability, as a result, there is
another problem that sintering density is difficult to increase. In
particular, since Ti-6Al-4V alloy has small plastic deformability,
it is known that sintering density is difficult increase by an
ordinary method in the powder method (See Reference 1 below).
[0007] Therefore, with an ordinary powder, dense titanium alloy
material is produced by a sintering method such as the Cold
Isostatic Press (hereinafter simply referred to as CIP) or the Hot
Isostatic Press (hereinafter simply referred to as HIP)
process.
[0008] However, even in the case in which sintering is performed by
the CIP and HIP processes, sometimes pores remain and sintering
density of titanium alloy produced is not increased. Regarding this
point, for example, a technique may be used in which strength or
toughness of alloy material processed by the CIP and HIP processes
is improved by adding B, Mo, W, Ta, Zr, Nb or Hf to the alloy
powder as a third component (See Reference 2 below).
[0009] However, an upper limit of remaining pores in titanium alloy
after sintering is controlled to be not more than 50 .mu.m in the
Reference 2. A dense alloy having further fine pores or having no
pores substantially is required as a material to which further
higher strength is required compared to conventional titanium
alloy.
[0010] Reference 1: Japanese Unexamined Patent Application
Publication No. Hei 02 (1990)-050172
[0011] Reference 2: Japanese Patent Laid Open No. Hei 05
(1993)-009630
SUMMARY OF THE INVENTION
[0012] An object of the present invention is to provide titanium
alloy powder having superior quality by the powder method using
titanium alloy scrap or titanium alloy ingot as a raw material,
titanium alloy material, and a process for production thereof.
[0013] As a result of the inventors researching about these
problems further in view of the above-mentioned circumstances, it
was found that titanium alloy complex powder having uniform
composition can be produced, by using the titanium alloy scrap or
titanium alloy ingot as a raw material, hydrogenating it to
generate hydrogenated titanium alloy, dehydrogenating it to
generate titanium alloy powder, and further adding copper powder,
chromium powder or iron powder, and thus the present invention has
been completed.
[0014] Furthermore, they've found that an apparent density of
titanium alloy complex powder having copper powder, chromium powder
or iron powder can be consolidated to not less than 99% of
theoretical density by CIP process and subsequent HIP process or by
HIP process after filling the titanium alloy complex powder into a
capsule, and thus, the present invention has been completed.
[0015] That is, titanium alloy complex powder of the present
invention has titanium alloy powder, and at least one kind of
metallic powder selected from copper powder, chromium powder and
iron powder added to the titanium alloy powder, wherein the added
amount of the metallic powder is in a range from 1 to 10 wt % in
the case in which one metallic powder is added, and the added
amount of the metallic powder is in a range from 1 to 20 wt % in
the case in which two or more metallic powders are added.
[0016] In the present invention, it is desirable that the titanium
alloy powder contain aluminum and vanadium, or contain at least one
kind selected from zirconium, tin, molybdenum, iron and chromium in
addition to aluminum and vanadium.
[0017] In the present invention, it is desirable that the average
particle size of the copper powder, chromium powder or iron powder
be in a range from 1 to 300 .mu.m.
[0018] A process for production of titanium alloy complex powder of
the present invention has steps of hydrogenating titanium alloy raw
material to generate hydrogenated titanium alloy powder,
dehydrogenating the hydrogenated titanium alloy powder to generate
titanium alloy powder, and adding at least one of copper powder,
chromium powder or iron powder.
[0019] A process for production of titanium alloy material of the
present invention has steps of consolidating the titanium alloy
complex powder by CIP process and subsequent HIP process, or by HIP
process after filling into a capsule.
[0020] A titanium alloy material of the present invention is
produced by using titanium alloy powder as a raw material which is
produced by the process having steps of hydrogenating titanium
alloy raw material to generate hydrogenated titanium alloy powder,
dehydrogenating the hydrogenated titanium alloy powder to generate
titanium alloy powder, and adding at least one of copper powder,
chromium powder or iron powder.
[0021] In the present invention, it is desirable that a true
density of the titanium alloy material produced by the above
process be not less than 99% of theoretical density.
[0022] As mentioned above, since titanium alloy material of the
present invention is produced not via remelting and solidifying,
segregation of copper, chromium or iron does not occur, and as a
result, although it has been conventionally regarded as difficult
to disperse or solid solve by the remelting method, copper,
chromium or iron can be added at high concentration. Furthermore,
since reactions between titanium alloy powder and copper powder,
chromium powder or iron powder occur in consolidating processes,
and no special technique such as mechanical alloying or the like is
necessary in the mixing step.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 is a flow chart diagram showing the process for
production of titanium alloy material of the present invention.
[0024] FIG. 2 is a SEM photograph of Ti-6Al-4V alloy powder
produced by the hydrogenating and dehydrogenating processes.
[0025] FIG. 3 is a SEM photograph of titanium alloy complex powder
in which copper powder is added to titanium alloy powder.
[0026] FIG. 4 is a result of EPMA analysis of 5% Cu containing
Ti-6Al-4V alloy material in width direction.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] Preferable embodiments of the present invention are
explained below with reference to the drawings.
[0028] FIG. 1 shows a desirable embodiment for production of
titanium alloy material of the present invention. As a raw material
of titanium alloy, a mixture consisting of a master alloy powder
having desired components produced in another process and pure
titanium powder can be used; however, since the master alloy powder
is expensive, it is desirable to use an alloy scrap or titanium
alloy ingot originally having desired components such as titanium
alloy chips, titanium alloy forged chips, edge material of titanium
alloy rods or the like as the raw material in the present invention
from the viewpoint of cost reduction.
[0029] It is desirable that lengths or dimensions of these titanium
alloy scraps or titanium alloy ingots (hereinafter simply referred
to as "titanium alloy raw material") be controlled to a
predetermined size beforehand. For example, it is desirable to cut
the material up at not more than 100 mm beforehand in the case of
alloy chips. By cutting at the above-mentioned length, subsequent
hydrogenating process can be efficiently promoted. In addition, in
the case of block shaped alloy scrap such as the forged chips,
there is no difficulty as long as it has a size by beforehand
processing so that it can be placed into a hydrogenating furnace.
In the case in which the alloy raw material is titanium alloy
ingot, it is desirable to treat it so as to be cut chips.
[0030] The titanium alloy raw material treated and controlled as
mentioned above, is brought into the hydrogenating process under a
hydrogen atmosphere. The hydrogenating process is desirably
performed in a temperature range from 500 to 650.degree. C. Since
hydrogenating process reaction of alloy raw material is an
exothermic reaction, any heating operation by a heating furnace is
not necessary accompanied by promotion of hydrogenating reaction,
and thus hydrogenating reaction can be promoted automatically.
[0031] The titanium alloy raw material which is hydrogenation
treated (hereinafter simply referred to as "hydrogenated titanium
alloy") is then cooled to room temperature, and it is desirably
ground and sifted until hydrogenated titanium powder has a
predetermined particle size under an inert atmosphere such as argon
gas or the like.
[0032] By performing grinding and sifting processes of the
hydrogenated titanium alloy powder, subsequent consolidating
process of titanium alloy complex powder by CIP process and
subsequent HIP process or by HIP process after filling titanium
alloy complex powder into a capsule, can be effectively
promoted.
[0033] Next, hydrogenated titanium alloy powder that is ground and
sifted is desirably heated until it reaches a high temperature
range in an atmosphere held at reduced pressure. The temperature of
dehydrogenating process is desirably performed in a range from 500
to 800.degree. C. Since the dehydrogenation reaction is an
endothermic reaction, in contrast to the above-mentioned
hydrogenation reaction, heating operation is necessary until
hydrogen is completely generated from hydrogenated titanium alloy
powder. By the operation, titanium alloy powder of the present
invention can be obtained.
[0034] It is desirable that titanium alloy powder of the present
invention be controlled in a range from 1 to 300 .mu.m.
[0035] Titanium alloy powder obtained by the above-mentioned
dehydrogenating process is sometimes sintered together, and in this
case, it is desirable that the grinding and sifting processes be
performed again.
[0036] After dehydrogenating process, by adding copper powder,
chromium powder or iron powder which is a third component used in
the present invention to the titanium alloy powder ground and
sifted, the titanium alloy complex powder of the present invention
can be obtained. It is desirable that the titanium alloy complex
powder of which grinding and sifting processes be performed and
copper powder, chromium powder or iron powder be added controlled
in a range from 1 to 300 .mu.m.
[0037] In the present invention, it is desirable that the
consolidating process be performed by combining CIP and HIP
appropriately.
[0038] For example, it is desirable that titanium alloy complex
powder obtained in the above-mentioned method be filled in a CIP
rubber, treated at 100 to 200 MPa, then filled in a HIP capsule,
and HIP treated at a temperature not more than .beta.
transformation point at 50 to 200 MPa for 1 to 5 hours. After such
CIP process and subsequent HIP process, consolidated titanium alloy
material can be obtained.
[0039] Alternatively, it is desirable that titanium alloy complex
powder obtained in the above-mentioned method be filled in a HIP
capsule and HIP treated at a temperature not higher than .beta.
transformation point at pressure from 50 to 200 MPa for 1 to 5
hours without CIP process. Consolidated titanium alloy material can
also be obtained by only the HIP process.
[0040] Next, function and effect by adding copper powder, chromium
powder or iron powder to titanium alloy powder is explained.
Function and effect by adding copper powder, chromium powder or
iron powder
[0041] It is expected that mechanical properties, formability and
sintering property of material are improved by adding copper
powder, chromium powder or iron powder to titanium alloy
powder.
[0042] In the present invention, it is desirable that copper
powder, chromium powder or iron powder be added to titanium alloy
powder as a third component. It is desirable that the ratio of
adding be 1 to 10% of titanium alloy powder weight in the case in
which one kind of these metallic powders is added. In addition, it
is desirable that the total ratio of adding be 1 to 20% of titanium
alloy powder weight in the case in which two kinds or more of these
metallic powders are added.
[0043] In the case in which iron or chromium is originally
contained in titanium alloy powder, it is desirable to add so that
the sum of the content of iron or chromium originally contained in
titanium alloy and a content of iron or chromium added later is in
a range from 1 to 10%.
[0044] In the case in which addition ratio of copper powder,
chromium powder or iron powder which is the third component and is
alone added to titanium alloy powder is not more than 1%, effect of
the consolidation cannot be exhibited sufficiently in the
consolidating process in the sintering process. On the other hand,
in the case in which addition ratio of copper powder, chromium
powder or iron powder is more than 10%, strength of titanium alloy
is undesirably deteriorated.
[0045] In the case in which plural third components are added to
titanium alloy powder, a range of 1 to 20% is desirable for a
similar reason.
[0046] In the case in which copper, chromium or iron is originally
contained in titanium alloy, it is desirable to add so that sum of
the content of copper, chromium or iron originally contained in
titanium alloy and a content of the metals added later is in a
range from 1 to 20%.
[0047] It is desirable that copper powder, chromium powder or iron
powder used in the present invention has a purity of 2N5 to
4N5.
[0048] Since titanium alloy powder has low formability and forming
by a simple mold pressing or the like is difficult, CIP process is
required. A compact which is CIP treated is sensitive to CIP
pressure, strength is decreased by a pressing force less than 100
MPa, and appropriate compact cannot be obtained.
[0049] However, strength of a compact is increased if copper
powder, chromium powder or iron powder is added to titanium alloy
powder. As a result, shape of the compact can be maintained even by
a pressing force not greater than 100 MPa. It is considered that
natural low deformability of titanium alloy powder is improved by
adding copper powder, chromium powder or iron powder.
[0050] Deformability of titanium alloy powder to which copper
powder, chromium powder or iron powder is added is improved, and as
a result, sintering property is also superior.
[0051] Furthermore, by performing CIP process and subsequent HIP
process, or by filling into a capsule and performing HIP process,
to titanium alloy powder to which copper powder, chromium powder or
iron powder is added, a sintered body not having voids and having
density ratio not less than 99% of theoretical density can be
obtained. It is considered that copper powder, chromium powder or
iron powder functions as a sintering promoting agent.
[0052] Furthermore, by regulating addition ratio of copper powder,
chromium powder or iron powder in the above range, and by
performing CIP process and subsequent HIP process, or by filling
into a capsule and performing HIP process, mechanical properties of
a titanium alloy material which is treated by consolidating can be
efficiently maintained. This is due to a solid solute enhancement
effect by addition of copper powder, chromium powder or iron
powder.
[0053] As the copper powder, chromium powder or iron powder added
to titanium alloy powder, commercially available powder sample can
be used. In the case in which the powder sample is difficult to
prepare, powder that is obtained by grinding a block sample and
then sifting can be used.
[0054] Titanium alloy powder to which copper powder, chromium
powder or iron powder is added is consolidated by performing CIP
process and subsequent HIP process, or by performing HIP process
after filling titanium alloy powder into a capsule.
[0055] For example, in the case of an alloy in which copper powder,
chromium powder or iron powder is added to Ti-6Al-4V alloy, it is
desirable to perform CIP process at 900.degree. C. which is not
higher than .beta. transformation point and at hydrostatic pressure
of 100 to 200 MPa and then to perform HIP process at a hydrostatic
pressure of 100 MPa for 1 hour.
[0056] Furthermore, for example, in the case of an alloy in which
copper powder, chromium powder or iron powder is added to Ti-6Al-4V
alloy, it is desirable to perform HIP process at 900.degree. C.
which is not higher than the .beta. transformation point and at a
hydrostatic pressure of 100 MPa for 1 hour after filling the
powders into the capsule. Titanium alloy material having a density
not less than 99% can be obtained by such consolidating
process.
[0057] Copper powder, chromium powder or iron powder added in
titanium alloy powder is dispersed in titanium of alloy material
matrix during a consolidating process, and as a result, alloy in
which atoms of copper, chromium or iron are uniformly solid solved
in titanium alloy can be produced.
[0058] By the present invention, copper, chromium or iron that is
solid solved in titanium alloy can be solid solved at high ratio
compared to a conventional remelting method, that is, 1 to 10 wt %
in single powder addition and 1 to 20 wt % in plural powder
addition. As a result, mechanical properties of titanium alloy
material can be effectively controlled.
[0059] Furthermore, in the present invention, titanium alloy such
as Ti-6Al-4V alloy, Ti-3Al-2.5V alloy, Ti-6Al-2Sn-4Zr-6Mo alloy,
Ti-6Al-6V-2Sn alloy, Ti-10V-2Fe-3A1 alloy (10-2-3),
Ti-5Al-4V-0.6Mo-0.4Fe alloy (Ti metal 54M), Ti-4.5Al-3V-2Fe-2Mo
alloy (SP700), Ti-15V-3Cr-3Al-3Sn alloy (15-3-3-3),
Ti-4Al-2.5V-1.5Fe alloy (ATI425), Ti-5Al-5V-5Mo-3Cr alloy (Ti-5553)
can be used as the above mentioned raw material of titanium alloy
powder.
[0060] Mechanical properties of titanium alloy material containing
copper, chromium or iron and being consolidated by the
above-mentioned method can be further controlled by subsequent
processing such as rolling, extrusion or drawing and heat
process.
EXAMPLES
[0061] Practical examples of production of titanium alloy powder
are explained below.
Example 1
[0062] Scrap cut chips of Ti-6Al-4V alloy were cut into chips
having lengths not greater than 10 mm. The chips were inserted into
a container and the container was set in a furnace. After vacuum
evacuation inside the furnace, heating was started, hydrogen was
induced into the furnace after the temperature inside the furnace
reached 300.degree. C., and heating was continued until 650.degree.
C. while maintaining the inside of the furnace in a slightly
pressurized condition by hydrogen. During this process, since
Ti-6Al-4V alloy scrap chips and hydrogen are reacted and
temperature inside the furnace is increased, heater output was set
at 0, and the condition was maintained as it was until the reaction
was completed.
[0063] After the reaction was completed, the furnace was allowed to
cool and the material was taken out. Confirmation was by X-ray
diffraction, since only peaks of hydrogenated titanium were
detected, and it was confirmed that all the material was converted
into hydrogenate. Grinding this hydrogenate under an argon gas
atmosphere and sifting by a sifter of 300 mesh yielded hydrogenated
titanium alloy powder having a particle size not greater than 48
.mu.m. This hydrogenated titanium alloy powder was inserted in a
container made of titanium, and dehydrogenation process was
performed in a vacuum heating furnace. Starting heating after
vacuum evacuation, dehydrogenation reaction in which hydrogen gas
was separated occurred at about 300.degree. C. Heating was
continued to increase the temperature up to 500.degree. C., and
then 600.degree. C., and dehydrogenation was promoted. Since the
dehydrogenation reaction is an endothermic reaction, it is
important to maintain temperature inside the furnace at a constant
level to perform dehydrogenation efficiently. When the temperature
was held at 650.degree. C. for 1 hour, the degree of vacuum was
recovered. Since a vacuum degree of 1.times.10.sup.-3 mbar was
obtained, heating was stopped, and it was cooled. It was confirmed
that the obtained powder was Ti-6Al-4V titanium alloy powder by
X-ray diffraction. Furthermore, since part of the powder was
aggregated, the aggregation was crushed by a crushing machine to
obtain titanium alloy powder of not more than 300 .mu.m. FIG. 2
shows an SEM photograph of titanium alloy powder obtained as above.
It was confirmed that alloy powder having relatively even particle
size can be obtained by the method of the present invention in the
photograph.
Example 2
[0064] Electrolytic copper powder (particle size: not greater than
45 .mu.m, produced by JX Nippon Mining & Metals Corporation)
was added to titanium alloy powder of Example 1 at 5 wt % of
titanium alloy powder, and they were mixed with a V-type mixing
machine. FIG. 3 shows an SEM photograph of titanium alloy complex
powder obtained as above. It was confirmed that titanium alloy
complex powder having relatively even particle size can be obtained
by the method of the present invention in the photograph. Maximal
particle size of obtained mixture powder was 300 .mu.m, and average
particle size was 60 .mu.m.
Example 3
[0065] Cu-added titanium alloy powder of Example 2 was filled in a
CIP rubber, and CIP treated at 100 MPa. Density of the CIP compact
was 65%. It has strength sufficient to be self-supported, and it
was never broken during handling.
[0066] The CIP compact was encapsulated in a soft steel capsule and
HIP treated. Conditions of HIP were 900.degree. C., 100 MPa and 1
hr. After HIP process, titanium material was taken out and its
density was measured, and it was not less than 99%. Density
mentioned here means the ratio of apparent density against the
theoretical density.
Example 3-2
[0067] Cu-added titanium alloy powder of Example 2 was encapsulated
in a soft steel capsule and HIP treated. Conditions of HIP were
900.degree. C., 100 MPa and 1 hr. After HIP process, titanium alloy
material was taken out and its density was measured, and it was not
less than 99%. Density mentioned here means the ratio of apparent
density against the theoretical density.
Example 4
[0068] Tensile test and hardness measuring test of titanium alloy
material of Example 3 were performed. 0.2% proof stress was 1200
MPa, tensile strength was 1300 MPa, and elongation was 10%. It was
confirmed that both 0.2% proof stress and tensile strength were not
less than 20% stronger than Cu-not added Ti-6Al-4V alloy annealed
material produced by the remelting method. The Vickers hardness was
465.
[0069] Titanium alloy material of Example 3 was analyzed by EPMA
along a range of 10.5 mm to confirm variation of each component of
Ti, Al, V and Cu, and the results are shown in FIG. 4. It is
confirmed that concentration of Cu is almost uniform around 5%
along the analyzed range of 10.5 mm.
Example 5
[0070] Chromium powder was added to titanium alloy powder of
Example 1 at 5 wt % of titanium alloy powder to obtain Cr
containing titanium alloy powder. Cr powder was prepared by
crushing electrolytic chromium powder produced by Japan Metals
& Chemicals Co., Ltd., and sifting it by using a sifter of 50
mesh. Cr containing titanium alloy material was obtained by CIP
process and subsequent HIP process in a similar conditions of
Example 3. Density of the material was not less than 99%.
Example 5-2
[0071] Chromium added titanium alloy powder of Example 5 was
encapsulated in a soft steel capsule and HIP process was performed.
HIP condition was 900.degree. C., 100 MPa, and 1 hour. After HIP
process, titanium alloy material was taken out and the density was
measured, and the density was not less than 99%.
Example 6
[0072] Iron powder was added to titanium alloy powder of Example 1
at 5 wt % of titanium alloy powder to obtain Fe containing titanium
alloy powder. Fe powder was commercially available atomized iron
powder, and its average particle diameter was 4 .mu.m. Fe
containing titanium alloy material was obtained by CIP process and
subsequent HIP process in a similar conditions of Example 3.
Density of the material was not less than 99%.
Example 6-2
[0073] Iron added titanium alloy powder of Example 6 was
encapsulated in a soft steel capsule and HIP process was performed.
HIP conditions were 900.degree. C., 100 MPa, and 1 hour. After HIP
process, titanium alloy material was taken out and the density was
measured, and the density was not less than 99%.
Example 7
[0074] Cu powder and Fe powder were added to titanium alloy powder
of Example 1 at 5 wt % (each powder), 10 wt % (total powders of
Cu+Fe) of titanium alloy powder to obtain Cu--Fe containing
titanium alloy powder. Cu powder and Fe powder were the same
powders as in Examples 2 and 6 respectively. Cu--Fe containing
titanium alloy material was obtained by CIP process and subsequent
HIP process in the similar conditions of Example 3. Density of the
material was not less than 99%.
Example 7-2
[0075] Cu powder and Fe powder added titanium alloy powder of
Example 7 was encapsulated in a soft steel capsule and HIP process
was performed. HIP conditions were 900.degree. C., 100 MPa, and 1
hour. After HIP process, titanium alloy material was taken out and
the density was measured, and the density was not less than
99%.
Example 8
[0076] Cu powder and Cr powder were added to titanium alloy powder
of Example 1 at 5 wt % (each powder), 10 wt % (total powders of
Cu+Cr) of titanium alloy powder to obtain Cu--Cr containing
titanium alloy powder. Cu powder and Cr powder were the same
powders as in Examples 2 and 5 respectively. Cu--Cr containing
titanium alloy material was obtained by CIP process and subsequent
HIP process in the similar conditions of Example 3. Density of the
material was not less than 99%.
Example 8-2
[0077] Cu powder and Cr powder added titanium alloy powder of
Example 8 was encapsulated in a soft steel capsule and HIP process
was performed. HIP condition was 900.degree. C., 100 MPa, and 1
hour. After HIP process, titanium alloy material was taken out and
the density was measured, and the density was not less than
99%.
Example 9
[0078] Cr powder and Fe powder were added to titanium alloy powder
of Example 1 at 5 wt % (each powder), 10 wt % (total powders of
Cr+Fe) of titanium alloy powder to obtain Cr--Fe containing
titanium alloy powder. Cr powder and Fe powder were the same
powders as in Examples 5 and 6 respectively. Cr--Fe containing
titanium alloy material was obtained by CIP process and subsequent
HIP process in the similar conditions of Example 3. Density of the
material was not less than 99%.
Example 9-2
[0079] Cr powder and Fe powder added titanium alloy powder of
Example 9 was encapsulated in a soft steel capsule and HIP process
was performed. HIP conditions were 900.degree. C., 100 MPa, and 1
hour. After HIP process, titanium alloy material was taken out and
the density was measured, and the density was not less than
99%.
Example 10
[0080] Cu powder, Cr powder and Fe powder were added to titanium
alloy powder of Example 1 at 4 wt % (each powder), 12 wt % (total
powders of Cu+Cr+Fe) of titanium alloy powder to obtain Cu--Cr--Fe
containing titanium alloy powder. Cu powder, Cr powder and Fe
powder were the same powders as in Examples 2, 5 and 6
respectively. Cu--Cr--Fe containing titanium alloy material was
obtained by CIP process and subsequent HIP process in the similar
conditions of Example 3. Density of the material was not less than
99%.
Example 10-2
[0081] Cu powder, Cr powder and Fe powder added titanium alloy
powder of Example 10 was encapsulated in a soft steel capsule and
HIP process was performed. HIP conditions was 900.degree. C., 100
MPa, and 1 hour. After HIP process, titanium alloy material was
taken out and the density was measured, and the density was not
less than 99%.
Example 11
[0082] Cu powder was each added at 1%, 3%, 8% and 10% in a way
completely similar to that of Example 2 to obtain four samples of
Cu containing titanium alloy powder. Cu containing titanium alloy
material was obtained by CIP process and subsequent HIP process in
similar conditions of Example 3. Densities of all the materials
were not less than 99%. Vickers hardnesses thereof were measured,
and the results are shown in Table 1. In Table 1, the result of 5
wt % containing alloy of Example 4 is also shown.
Example 11-2
[0083] Each of Cu powder added titanium alloy powder samples in
which Cu powder is each added so as to be 1%, 3%, 8% and 10% Cu
powder content shown in Example 11, was encapsulated in a soft
steel capsule and HIP process was performed. HIP condition was
900.degree. C., 100 MPa, and 1 hour. After HIP process, titanium
alloy material was taken out and the density was measured, and the
density was not less than 99%. Vickers hardnesses thereof were
measured, and the results are shown in Table 2. In Table 2, the
result of 5 wt % containing alloy of Example 3-2 is also shown.
TABLE-US-00001 TABLE 1 Cu content 1% 3% 5% 8% 10% Vickers hardness
350 380 465 480 435
TABLE-US-00002 TABLE 2 Cu content 1% 3% 5% 8% 10% Vickers hardness
351 375 463 482 440
Comparative Example 1
[0084] Titanium alloy powder the as same as in Example 1 was CIP
treated in a manner similar to that of Example 3 without adding Cu,
Cr and Fe powder. In the removal of CIP rubber, a CIP compact does
not have sufficient strength, and a corner part was broken right
after removal. Although the part was broken, an attempt was made to
handle the CIP compact so as to be encapsulated into a HIP
container. Then, the compact broke at a central part into two
pieces, and HIP process could not be performed. Next, CIP process
was performed similarly at 200 MPa of hydrostatic pressure, and the
compact could be completed. The compact was carefully handled to be
encapsulated in a HIP container, and HIP was performed in
conditions similar to that of Example 3. The compact was taken out
of the HIP container and density was measured, and the density was
98%.
Comparative Example 2
[0085] In conditions similar to those of Example 11, two samples in
which added ratio of copper powder to titanium alloy powder was
0.5% and 11% were made, their density ratio of sintered bodies
after sintering were measured, and the results are shown in Table
3. Density ratio of sintered body obtained in the case in which
added ratio of copper powder to titanium alloy powder was 0.5%, was
98.3%. In addition, density ratio of sintered body obtained in the
case in which added ratio of copper powder to titanium alloy powder
was 11%, was 98.2%. As explained so far, in the case in which added
ratio of copper powder to titanium alloy powder is in a range from
1 to 10%, density ratio of obtained sintered body is not less than
99% which is a good result. However, in the case in which added
ratio of copper powder to titanium alloy powder is less than 1% and
more than 10%, it is confirmed that the density ratio of a sintered
body may be deteriorated to less than 99%.
TABLE-US-00003 TABLE 3 wt % 0.5 1 3 8 10 11 Density ratio % 98.3
99.2 99.1 99.3 99.2 98.2
[0086] The present invention provides titanium alloy complex
powder, consolidated titanium alloy material and process for
production thereof, using titanium alloy scrap or ingot as a raw
material and by a hydrogenation and dehydrogenation method.
* * * * *