JP2000129301A - Prealloy power and production of sintered titanium alloy using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce prealloy powder contributing to the stable production of a sintered body of high performance in the case of being used as the prealloy powder of a sintered Ti alloy and moreover excellent in stability for oxidation and to provide a method for producing a sintered Ti alloy using it. SOLUTION: Ti powder 12 is blended with prealloy powder 13 essentially consisting of Al in a prescribed ratio to prepare raw material powder 15, the raw material powder 15 is compacted into a required shape, and it is thereafter sintered. By controlling the content of oxygen in the prealloy powder 13 to <=1.2 wt.%, a dense sintered Ti alloy having high strength can be obtd. Furthermore, by incorporating soap components essentially consisting of metallic soap and/or the Li salt of organic acid by 0.1 to 1 wt.% based on carbon equivalent, the stability for the oxidation of the prealloy powder 13 can remarkably be improved, in its turn, the increase of the content of oxygen in the prealloy powder 13 is increased, and the sintered Ti alloy of high performance can more stably be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-alloy powder, particularly to a pre-alloy powder used as a source of an alloy component when producing a Ti-based sintered body, and a method for producing a sintered Ti alloy using the same.

[0002]

2. Description of the Related Art Ti parts make use of their properties of light weight, high strength, and excellent corrosion resistance.
Widely used in various fields. However,
Since pure Ti does not have high strength, it is often used in the form of a Ti alloy having improved mechanical properties by blending alloying elements. A typical example of such an alloy element is Al. Al has a large solid solubility in Ti, has a high solid solution strengthening ability, and improves the high temperature strength and creep resistance of the alloy. Therefore, Al is added to most of Ti-based practical alloys. Typical ones are, for example, Ti-6Al
-4V alloy and the like.

On the other hand, Ti is poor in workability at room temperature, and the production of parts by cutting has the disadvantage of low material yield.
Therefore, as a method with higher yield, application of a so-called powder metallurgy method in which a Ti metal powder is formed into a predetermined shape and then sintered to obtain a Ti part has been attempted.
Here, when manufacturing a sintered body of a Ti alloy, using an alloy powder as a raw material powder is uneconomical because an alloy melting step and a pulverizing step are newly required. Therefore, T
In many cases, a method of blending a powder of an alloying element with an i-powder and alloying it at a sintering stage has been adopted.

Here, when Al is compounded as an alloying element, if it is compounded in the form of a simple powder of Al, the melting point of Ti becomes A
Since Al is considerably higher than Al, the aluminum is first dissolved during sintering, and a homogeneous alloy cannot be obtained. Therefore, Al is often compounded in the form of a so-called pre-alloy powder which has been alloyed with another alloy element in advance. For example,
When a Ti-6Al-4V alloy part is manufactured by sintering, an Al-40% by weight V alloy powder is used as a pre-alloy powder.

[0005] Sintered Ti alloy parts have a high material yield, but have the disadvantage that their mechanical properties tend to vary depending on the impurity concentration level in the raw material powder. In particular, when the oxygen content in the powder is high, there is a problem that the densification of the sintered body is hindered and the strength is significantly reduced. In this case, in order to prevent the amount of oxygen in the raw material powder from increasing, in addition to thoroughly controlling the process so that the powder is not exposed to the air for a long time, the stability of the powder itself against oxidation is improved. Doing so is also an important point.

[0006]

However, simply controlling the oxygen concentration in the raw material powder may not always stabilize the mechanical properties of the obtained sintered Ti alloy. For example, even if the oxygen concentration is the same, a sintered body having relatively high strength can be obtained in one case, but the strength may be completely insufficient in another case. According to the study of the present inventors, this tendency is
It was found that the effect was particularly remarkable in the case of sintering by mixing a prealloy powder with a Ti powder.

[0007] When a Ti powder and a pre-alloy powder mainly composed of Al are used, as a specific method for improving the oxidative stability, for example, Japanese Unexamined Patent Publication (Kokai) No. 1-198401 discloses Ti powder particles and pre-alloy powder. A method of coating particles (different metal particles) with an organic binder to prevent surface oxidation is disclosed. Here, as the organic binder, for example, paraffinic, aromatic hydrocarbon-based, alcohol-based, carboxylic acid-based low-molecular compounds and various waxes are used, and the effect of improving the oxidation stability of the pre-alloy powder is used. Is not always enough.

[0008] An object of the present invention is to provide a pre-alloy which, when used as a pre-alloy powder of a sintered Ti alloy, stably produces a high-performance sintered body and has excellent oxidation stability. An object of the present invention is to provide a powder and a method for producing a sintered Ti alloy using the powder.

[0009]

Means for Solving the Problems and Action / Effect In order to solve the above problems, a first structure of the pre-alloy powder of the present invention is made of an alloy containing at least one of Al and Mg as a main component. , A soap component mainly composed of a metal soap and / or a Li salt of an organic acid is 0.1 to 0.1% by carbon equivalent.
１．２1.2% by weight, and the oxygen content is 1.2% by weight
It is characterized by the following.

The second structure is composed of an alloy containing at least one of Al and Mg as a main component, and a metal component and / or a soap component mainly composed of a Li salt of an organic acid are converted to carbon equivalent. 0.1 to 1.2% by weight, and when heated at 500 ° C. for 1 hour, the weight loss mainly due to the evaporation of the soap component is 0.3 to 1.2% by weight. And

[0011] The phrase "having at least one of Al and Mg as a main component" means that one or both of Al and Mg are the alloy components having the highest weight content. means. Further, the alloy may be an alloy containing only one of Al and Mg.

Further, a third structure of the pre-alloy powder of the present invention is that a sintered Ti alloy used as a source of an alloying additive element of a sintered Ti alloy by being added to a raw material powder of the sintered Ti alloy.
A pre-alloy powder for an alloy, characterized by containing a soap component mainly composed of a metal soap and / or a Li salt of an organic acid in a carbon equivalent of 0.1 to 1.2% by weight. In the third configuration, the main component of the pre-alloy powder may be at least one of Al and Mg, or may be another metal component having a problem in oxidation resistance.

Further, the method for producing a sintered Ti alloy according to the present invention is characterized in that a predetermined amount of the prealloy powder of the present invention is mixed with Ti powder, which is then formed into a desired shape and then sintered. .

The common feature of the prealloyed powder of the present invention is that a soap component mainly composed of a metal soap and / or a Li salt of an organic acid is used in an amount of 0.1 to 0.1 in carbon equivalent.
That is, the content is 1.2% by weight. In the present invention, the metal soap is generally defined as a metal salt of an organic acid excluding an alkali metal salt. By including such a soap component in the indicated range, the stability of the pre-alloy powder against oxidation can be remarkably improved, and the increase in the amount of oxygen in the pre-alloy powder is suppressed, so that a high performance sintered Ti alloy is obtained. Can be manufactured more stably. Further, a dense and high-strength sintered Ti alloy can be obtained by the method for producing a sintered Ti alloy of the present invention using such a pre-alloy powder.

Japanese Patent Application Laid-Open No. 1-198401 discloses a method of coating Ti powder particles and pre-alloy powder particles (different metal particles) with various organic binders, as described above. However, the organic binders used there are paraffin-based, aromatic hydrocarbon-based,
It is an alcohol-based or carboxylic acid-based low-molecular compound or various waxes, and consists only of molecules having no group exhibiting a remarkable adsorption action with the surface of the metal powder particles. Therefore, it is considered that the formed coating film has weak adhesion and lacks uniformity, and does not necessarily have sufficient oxygen blocking ability. In this case, it is conceivable to improve the oxidation stability by increasing the coating thickness, but the total amount of the organic binder added, and hence the residual amount of carbon in the sintered body increases, and the strength and the like decrease. It is easy to invite.

However, as shown in FIG. 2, the soap component used in the present invention is a surfactant component having a hydrophilic group 20 composed of metal ions and a hydrophobic group 21 mainly composed of organic acid molecules. The hydrophilic groups 20 are adsorbed on the surface of the metal particles P, and a thin and uniform coating film having excellent adhesion can be formed. As a result, it is presumed that a coating film excellent in oxygen blocking ability is realized even with a small amount of addition, and the oxidation stability of the powder is improved. In addition, since the coating film has hydrophobic groups arranged on its surface, it hardly generates an adhesive force due to hydrogen bonding or the like, and has an effect of improving the releasability at the time of molding.

The metal soap component usable in the present invention is, for example, an organic acid component comprising naphthenic acid (naphthate),
Lauric acid (laurate), stearic acid (stearate), oleic acid (oleate), 2-ethylhexanoic acid (octate), linseed oil or soybean oil fatty acid (linoleate), tall oil (tolate), rosin (resinate) And the like. In addition, the following types of metals can be exemplified.・ Naphthate (Al, Ca, Co, Cu, Fe, P
b, Mn, Zn, etc.) Resinates (Al, Ca, Co, Cu, Fe, P
b, Mn, Zn, etc.) Linoleate (Co, Fe, Pb, Mn, etc.) Stearate (Ca, Zn, etc.) Octate (Ca, Co, Fe, Pb, Mn, Zn)
Etc.)-Torrate type (Ca, Co, Fe, Pb, Mn, Zn)
Etc.) Examples of the organic acid Li salt include Li stearate and the like. Of these, stearic acid Z
n, Li stearate and Ca stearate can be particularly preferably used to effectively bring out the above-mentioned effects.

As the soap component, one kind may be used alone, or two or more kinds may be used in combination. Further, the method of compounding the soap component into the pre-alloy powder is, for example, a method of adding to the pulverized pre-alloy powder and mixing using various known mixing devices, and a method of adding alloy during pulverization of the pre-alloy powder and pulverizing the alloy and the soap There is a method of performing mixing simultaneously. In the latter case, there is an advantage that the soap mixing step can be omitted, but it is necessary to appropriately adjust the mixing conditions and the like so that the reaction between the carbon component of the soap and the alloy powder does not excessively occur.

If the amount of the soap component is less than 0.1% by weight in terms of carbon equivalent, the effect of improving the oxidative stability of the powder by the soap component cannot be expected sufficiently. On the other hand, when the content exceeds 1.2% by weight, the residual amount of carbon in the sintered body increases, and the strength or the like tends to be reduced. In addition, as in the case where the oxidation proceeds, the carbon content is concentrated on the surface of the pre-alloy powder particles to prevent diffusion during sintering,
It is also conceivable that the density is reduced. Preferably, the compounding amount of the soap component is 0.1 to 1.0% by weight in carbon equivalent, more preferably 0.5 to 0.1% by weight.
The content is preferably 8% by weight. When a carbon component not derived from the soap component is contained, such as an unavoidable impurity in the raw material, the carbon content in the pre-alloy powder including the one derived from the soap component is 1.2% by weight or less. Is desirable for the same reason.

When the soap component is contained in the pre-alloy powder, when the soap component is heated at 500 ° C. for 1 hour,
Weight loss mainly due to evaporation of soap component is 0.3 ~
It is good to be 1.5% by weight. If the weight loss is less than 0.3% by weight, the effect of improving the oxidative stability of the powder by the soap component cannot be expected sufficiently. On the other hand, when the content exceeds 1.5% by weight, the residual amount of carbon in the sintered body increases, and the strength or the like tends to be reduced.
The weight loss is desirably 0.3 to 1.3% by weight, and more desirably 0.3 to 0.7% by weight. In addition, whether the weight loss during heating is mainly due to the evaporation of the soap component, when analyzing the gas composition generated by evaporation, the above-described various soap components, or the above-mentioned soap can be a hydrophobic group. It can be specified by examining whether or not various organic acid molecules are the main components.

When the main component element is Al and / or Mg, the alloy element component in the pre-alloy powder is as follows:
Specifically, it may be one or more selected from V, Cr, Zr, Nb, Mo, W, Si, and Sn (hereinafter, these are collectively referred to as dependent additive element components). The amount can be adjusted, for example, in the range of 0.2 to 40% by weight. V, Cr, Zr, N as dependent additive element components
b, Mo, W, Si or Sn are all known T
It is contained in the i-alloy. Although the role of each element differs depending on the composition of the finally obtained sintered Ti alloy, detailed descriptions thereof are omitted because they are all known contents. The dependent additive element component is generally a component having excellent oxidation resistance as compared with Al and Mg. When the content exceeds 40% by weight, the oxidation resistance of the alloy itself becomes good, and the above-described present invention In some cases, there is little point in applying a specific coating. On the other hand, if it is less than 0.2% by weight, the content of the dependent additive element component in the sintered Ti alloy is too low, and the effect of the additive may not be sufficiently obtained. The pre-alloy powder of the present invention may contain a dependent additive element other than the above. In the method for producing a sintered Ti alloy of the present invention, another auxiliary alloy component powder having a different component and composition may be added to the Ti powder in addition to the prealloy powder of the present invention.

The oxygen content in the pre-alloy powder is 1.2
% By weight or less. For example, it is well known that when the oxygen content increases, the strength of the sintered Ti alloy is impaired, and the oxygen content in the raw material powder has been conventionally controlled to prevent this problem. . However, in the technique of sintering a compounded powder of a Ti powder and a pre-alloy powder (hereinafter, simply referred to as a compounded powder), conventionally, only the average oxygen content of the compounded powder has been controlled. According to the results of extensive studies by the present inventors, even when the oxygen concentration of the Ti powder occupying the main component is low, when the oxygen concentration of the prealloy powder is increased to a certain value or more, specifically, 1.2 wt% or more, the overall It has been found that the densification of the sintered body is rapidly hindered and the strength is impaired even though the typical oxygen concentration is not so high. By limiting the oxygen content of the pre-alloy powder to 1.2% by weight or less, a dense and high-strength sintered Ti alloy can be obtained even if the amount of oxygen in the Ti powder varies to some extent.

Conventionally, the mechanical properties of the sintered Ti alloy using the compounded powder tended to fluctuate because the average oxygen content of the entire powder was emphasized because the control of the oxygen concentration level of the prealloyed powder was difficult. It is presumed that the cause was that the control was quiet. As described above, by controlling the oxygen concentration of the pre-alloyed powder to 1.2% by weight or less, it is possible to stably produce a sintered Ti alloy with high performance and little variation. In addition, when the oxygen concentration level of the pre-alloy powder is increased, the densification of the sintered body is prevented because the oxide layer on the surface of the pre-alloy powder particles is thickened, and the diffusion of alloy components is significantly prevented. It is speculated as one factor.

Next, the pre-alloy powder of the present invention can be produced by various known methods. For example, as shown in FIG.
After mixing and dissolving the raw materials, this is sprayed by a gas atomizing method or the like, and the particle size is 45 to 250 μm (for example, 180 μm
A method of producing a final pre-alloyed powder 13 by preparing a coarse powder 10) and then pulverizing the coarse powder 10 by various methods such as an attritor mill, a vibration mill or a ball mill.

The prealloy powder of the present invention has an average particle size of 1
The thickness is preferably 0 to 45 μm. If the average particle size is less than 10 μm, the specific surface area of the powder increases, the oxidation stability decreases, and it may be difficult to maintain the oxygen content at less than 1.2% by weight. On the other hand, when a compact is formed by press molding and sintered, if the average particle diameter is less than 10 μm, the density of the compact becomes difficult to increase, and as a result, the shrinkage during sintering becomes too large, and In some cases, it is difficult to ensure the dimensional accuracy of the unit. On the other hand, the average particle size is 45 μ
If it exceeds m, it is difficult to cause uniform component diffusion between the pre-alloy powder and the Ti powder during sintering, and the strength may be reduced due to non-uniform component concentration. The average particle size is preferably 10 to 20 μm, and more preferably 13 to 20 μm.

As the Ti powder used in the method for producing a sintered Ti alloy according to the present invention, a powder generally called a pure Ti powder can be used. However, C, N, O, Fe, Mg
And the like may be contained up to about 0.5% by weight in total. And the average particle size is 35-100μ
m. Average particle size is 35μm
If it is less than 10, the density of the molded body is difficult to increase, and as a result, the amount of shrinkage at the time of sintering becomes too large, and it may be difficult to secure the dimensional accuracy of the sintered body. On the other hand, 100μ
If it exceeds m, the moldability of the powder will deteriorate, and it will be difficult to uniformly disperse the pre-alloy powder, and the strength may be reduced due to non-uniform component concentrations.

Hereinafter, an example of the method for producing the sintered Ti alloy of the present invention will be described. First, as shown in FIG. 3, a predetermined amount of a Ti powder 12, a pre-alloy powder 13, and an auxiliary alloy element powder 14 are weighed as required and mixed by a mixer 16 (for example, an attritor). Powder) 15
Get. Next, this is shaped into a desired shape and sintered to obtain a sintered Ti alloy member. As a molding method, for example, as shown in FIG.
Die press molding, in which a compact is obtained by compressing the molded article, can be employed. Note that a cold isostatic pressing method (including a rubber pressing method) in which a rubber mold is filled with powder and hydraulically compressed may be used.

As shown in FIG. 5, a compound is prepared by mixing and kneading a resin binder with the raw material powder, and the compound is heated and heated to form a compound 15 ′.
Alternatively, a metal injection molding method may be used in which an injection molded body is produced by injecting into the cavity 106 of No. 5 and then debindered and then sintered. Furthermore, in addition to this, hot isostatic pressing,
Extrusion molding, hot pressing and the like can be employed.

[0029]

EXAMPLES The following experiments were conducted to confirm the effects of the present invention. (Example 1) Various prealloyed powders shown in Table 1 were prepared as follows. First, a predetermined amount of a raw material was blended and dissolved, and this was sprayed by a known gas atomizing method using argon gas to prepare a substantially spherical atomized powder having an average particle diameter of 180 μm. The material used was
Al metal (industrial pure Al, purity 99%), V metal (purity 99.8%), sponge Zr (industrial pure Zr, purity> 9)
8%), Sn metal (purity> 99.8%), Mo metal (purity> 99%), and Si (purity 98.4%). Then, by atomizing this atomized powder,
It was pulverized to an average particle size of 14 μm. The powder after pulverization is 6
The oxygen content was investigated by leaving it in the air at 0 ° C. and a relative humidity of 90% RH for various times. Including this, the amount of oxygen in the pre-alloy powder is identified by a known gas analysis method.

On the other hand, as auxiliary alloy element powders, Mo boride (MoB: purity 99%, average particle diameter 3 μm), boron alone (purity 99.5%, average particle diameter 5 μm), ferrovanadium powder (Fe-80V : 96% purity, average particle size 25
μm). Moreover, as Ti powder,
Industrial pure Ti powder (purity 99%, average particle size 42 μm) obtained by pulverizing sponge Ti was prepared. Note that Ti
The oxygen content of the powder is 0.1% by weight.

The above-mentioned Ti powder, pre-alloy powder and auxiliary alloy element powder were blended in such a ratio that a desired sintered body composition was obtained, and these were sufficiently mixed with an attritor to obtain a raw material powder. Then, the raw material powder was press-formed using a die press forming machine to obtain a molded product of a test specimen for a tensile test described later. Next, this is evacuated (10 ⁻⁴ to 10).
^-5 torr) at 1200 to 1300 ° C for 2 to ⁵ h
By sintering, sintered bodies of various compositions were obtained.

The density of the obtained sintered body was measured by the Archimedes method, and the outer surface thereof was polished to obtain a tensile test piece (powder having a thickness of 5 mm × a width of 5.7 mm × a parallel portion of 32 mm × a total length of 96.5 mm).・ Powder Metallurgy Association Standard 2
-64), a tensile test was performed at room temperature to determine the breaking strength. Table 1 shows the above results.

[0033]

[Table 1]

That is, it can be seen that the use of the prealloy powder having an oxygen content of 1.2% by weight or less increases the sintered body density and the strength.

Next, Al-40 as a pre-alloy powder
A wt% V alloy powder was prepared in the same manner as described above. The average particle size of the powder was 14 μm, and the oxygen content was 0.90% by weight. To this powder, various soap components shown in Table 2 or acura wax as an organic binder were blended in various ratios and mixed using an attritor. The amount of carbon in the powder after mixing was measured by a known gas analysis method. Further, 10 g of the powder was heated in the air at 500 ° C. for 1 hour, and the weight loss was measured. When the gas generated during the heating was analyzed by gas chromatography, it was found that the weight loss of the powder was mostly due to the evaporation or decomposition of the soap component or the organic binder incorporated therein.

Next, each of the above powders was treated at 60 ° C. and 90% relative humidity.
The sample was allowed to stand in the atmosphere of% RH for 48 hours, and the amount of increase in oxygen was determined from the change in the oxygen level before and after standing. The powder before standing was molded and sintered in the same manner as in Example 1, and the strength of the sintered body was measured. Table 2 shows the above results.

[0037]

[Table 2]

That is, it can be seen that the composition containing the soap component has a small increase in oxygen upon standing and is excellent in stability against oxidation. In this case, the oxidation suppression effect is:
The amount of soap component is converted to carbon content (carbon equivalent)
At 0.1% by weight or more. On the other hand, it is also found that the sintered body strength can be maintained at a relatively good value by setting the carbon content to 1.2% by weight or less.

(Example 2) Al as pre-alloy powder
A -40 wt% V alloy powder was prepared in the same manner as in Example 1. However, the average particle size of the powder was adjusted to various values of 8 to 50 μm by adjusting the pulverization time by the attritor mill. This was mixed with Ti powder so as to obtain an alloy composition of Ti-6Al-4V, and was die-pressed at a pressure of 4 ton / cm ² to obtain a cylindrical shaped body having a cross-sectional diameter of 20 mm. The height of the compact was measured. Next, this was placed in an argon atmosphere (780 torr).
By sintering at 1300 ° C. for 2 hours in the inside, a sintered body was obtained. The surface of the sintered body was polished into a test piece, and a compression test was performed using the test piece. The strength was measured by reading the 0.2% proof stress from the load-displacement curve. On the other hand, each powder was left in the air at 60 ° C. and a relative humidity of 90% RH for 48 hours, and the oxygen level before and after the standing was measured. Table 3 shows the above results.

[0040]

[Table 3]

That is, the average particle size of the pre-alloy powder was 1
It is understood that the oxidation stability is improved by setting the thickness to 0 μm or more. On the other hand, when the average particle size exceeded 45 μm, the strength of the molded article was slightly low, and chipping or the like was likely to occur during handling.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a preparation method by pulverizing a pre-alloy powder.

FIG. 2 is a diagram for estimating the action of a soap component.

FIG. 3 is an explanatory view showing a powder mixing process in a manufacturing process of a sintered Ti alloy using a pre-alloy powder.

FIG. 4 is an explanatory diagram of a manufacturing process of a sintered Ti alloy using die press molding.

FIG. 5 is an explanatory diagram of a manufacturing process of a sintered Ti alloy using an injection molding method.

[Explanation of symbols]

 12 Ti powder 13 Pre-alloy powder

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[Procedure amendment]

[Submission date] September 24, 1999 (1999.9.2)
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshinori Shibata 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Automobile Co., Ltd. Takao Okochi 3-418, Ubakoyama, Midori-ku, Nagoya-shi, Aichi (72) Inventor Moriki Aikawa 1-10-62-101 Minamigaoka, Chigusa-ku, Nagoya-shi, Aichi F-term 4K018 AA06 BA07 BA19 BB04 BC29 BC30 CA08

Claims (12)

[Claims] 1. A soap component mainly composed of an alloy containing at least one of Al and Mg as a main component and mainly containing a metal soap and / or a Li salt of an organic acid in a carbon equivalent of 0.1 to 1. 2% by weight, and the oxygen content is 1.
A pre-alloy powder characterized by being at most 2% by weight. 2. When a soap component mainly containing a metal soap and / or a Li salt of an organic acid is contained and heated at 500 ° C. for 1 hour, weight loss mainly due to evaporation of the soap component is reduced. The pre-alloy powder according to claim 1, wherein the amount is 0.3 to 1.5% by weight. 3. A soap component composed of an alloy containing at least one of Al and Mg as a main component and mainly containing a metal soap and / or a Li salt of an organic acid in a carbon equivalent of 0.1 to 1. A pre-alloy powder containing 2% by weight and having a weight loss of 0.3 to 1.5% by weight mainly due to evaporation of the soap component when heated at 500 ° C for 1 hour. 4. V, Cr, Zr, Nb, Mo, W, Si
And at least one selected from Sn and 0.2 to 40
The pre-alloy powder according to any one of claims 1 to 3, which is contained in a range of weight%. 5. A pre-alloyed powder for a sintered Ti alloy used as a source of an alloying additive element component of the sintered Ti alloy in a raw material powder of the sintered Ti alloy, wherein the metal soap and / or the organic A pre-alloy powder comprising a soap component mainly composed of an acid Li salt in an amount of 0.1 to 1.2% by weight in terms of carbon equivalent. 6. The pre-alloy powder according to claim 5, wherein the oxygen content is 1.2% by weight or less. 7. The pre-alloy powder according to claim 1, wherein the surface of the powder particles is coated with a coating film mainly composed of the soap component. 8. The pre-alloy powder according to claim 1, which has an average particle size of 10 to 45 μm. 9. The pre-alloy powder according to claim 1, which has an average particle size of 13 to 20 μm. 10. The pre-alloy powder according to claim 1, which has a carbon content of 1.2% by weight or less. 11. The soap component comprises stearic acid Z.
The prealloy powder according to any one of claims 1 to 10, wherein the prealloy powder is at least one selected from n, Li stearate, and Ca stearate. 12. A pre-alloyed powder according to any one of claims 1 to 11, which is blended in a predetermined amount with a Ti powder, which is formed into a desired shape and then sintered.
Alloy manufacturing method.