JPH04103732A - Manufacture of intermetallic compound al3 ti - Google Patents

Abstract

PURPOSE:To obtain the intermetallic compound of Ti and Al at high purity by pulverizing a Ti oxide and an Al oxide, executing mixing, allowing Ca to act on the above mixed powder to reduce it and thereafter removing by- products by a solvent. CONSTITUTION:In a primary stage, titanium and aluminum atoms in mixed titanium dioxide (TiO2) and aluminum oxide (Al2O3) are pulverized as fine as possible and are uniformly mixed. In a secondary stage, this oxide mixture is reduced by acting calcium or calcium hydride thereon at a high temp. in the temp. range of 1023 to 1473K (750 to 1200 deg.C). In this reducing stage, oxygen bonded with titanium and aluminum atoms is cut off by Ca, and simultaneously, the bond of Ti and Al is promoted. As a result, powdery intermetallic compound Al3Ti is synthesized together with calcium oxide and a Ca-Al allay. The CaO and Ca-Al allay by-produced in the third stage are melted away by a solvent such as water, an acid water soln. and ammonium chloride. Only the intermetallic compound Al3Ti is purely taken out.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention uses titanium (Ti) and aluminum (Al), which are highly strong and lightweight and are expected to be next-generation heat-resistant materials.
The present invention relates to a method for producing pure intermetallic compound Affi-Ti in large quantities at low cost.

A large amount of high purity Al produced by the method of the present invention
:l By using Ti, the intermetallic compound -
Al. It becomes possible to form Ti fine powder and large sintered bodies, which can contribute to the advancement of new material technology. These molded bodies are lightweight, have high strength, and are heat resistant, so they can be incorporated into various devices, such as aircraft, space-related equipment, marine-related equipment such as deep-sea boats, and magnetic levitation trains. Mechanical structural materials constituting transportation-related equipment, etc., high-temperature power generation devices such as turbine blades used in jet engines, automobile engines, generator turbines, etc.
It is expected that it will be used in various application fields.

(Prior Art) Regarding the characteristics of intermetallic compounds A l 3T i, intermetallic compounds have excellent heat resistance, corrosion resistance, and mechanical strength, and are lightweight, so they are used in aircraft, spacecraft, deep-sea boats, etc. It is expected to be a necessary next-generation high-performance material.

A1, Ti, which is an alloy of titanium (Ti) and aluminum (A2), has the lowest specific gravity among intermetallic compounds in which titanium and aluminum atoms are strongly bonded, and has high expectations among intermetallic compounds. ing.

Intermetallic compound Ti5A, which is expected to be applied as a next-generation intermetallic compound 1. TiA E, A l
A phase diagram of an alloy of titanium and aluminum containing +Ti is shown in FIG. From this, it is understood that AliTi (region 2 in FIG. 1) is directly formed from a liquid (region 3 in FIG. 1). This compound can be manufactured by a manufacturing method consisting of a combination of two methods, which are general alloy manufacturing methods: (1) pure metal manufacturing, and (2) melting, mixing, solidification, and solidification. In addition, another common method for producing intermetallic compounds, a method using sintering of metal powder, is also applied. This is a method in which fine powders of titanium metal and aluminum are mixed and pressure-molded to a composition of 25 mol% titanium and 75 mol% aluminum, and then heated at a temperature of about 1227° C. or less to cause a reaction. In this method, the sintering reaction rate is slow, and T is formed as a thin film on the surface of the Ti particles.
A such as i A 1 is formed and becomes an impurity, and can become a simple substance only when the molar ratio of titanium and aluminum is 1:3.
It is difficult to extract pure l 3T i.

Therefore, the conventional method for producing Al 3 Ti consists of a composite process in which a homogenization process is added to the above-mentioned method (1) and (2). FIG. 2 shows a schematic diagram of the entire process. This process will be explained in the order of steps as follows. First, the first step is to extract titanium and aluminum, which exist in the form of oxides, titanium dioxide and aluminum oxide, in the ore in the form of pure oxides, and through the respective smelting processes to produce metallic titanium and metallic aluminum. This is the process of obtaining This smelting process uses established industrial technology. The second step is a step in which titanium and aluminum metals are melted and mixed to a target composition of 25% titanium and 75% aluminum. The alloy liquid obtained by this method is cooled and solidified.

In the third step, by-products such as TiAf are decomposed by maintaining the temperature in the temperature range in which the A f x Ti solid shown in Fig. 1 stably exists, that is, at a temperature of about 1350°C or less, for a sufficiently long time. , the process waits for the diffusion and mixing of titanium and aluminum atoms to synthesize uniform Al+Ti.

(Problems to be Solved by the Invention) The conventional methods described above had several problems to be solved as listed below.

(1) An uneconomic process in which aluminum atoms, which are impurities present in titanium ore, and aluminum atoms, which are impurities present in titanium ore, are removed in a smelting process and then both titanium and aluminum are mixed again. becomes.

(2) The melting points of metallic titanium and metallic aluminum are 1943 K (1670'C) and 933 K (6
60°C), there is an extremely large difference, and advanced technology is required to melt the two. Furthermore, in order to mix titanium and aluminum, which are active metals, a technique is required to heat both at a high temperature close to 2000 K (1727° C.) and in a vacuum or an inert gas.

Further, at this time, the vapor pressure of aluminum becomes much higher than that of titanium, and since aluminum evaporates from the alloy liquid, it is difficult to uniformly obtain a large amount of Al z Ti having a predetermined composition.

(3) Even if heat treatment is performed in the stable temperature range of Af 3 Ti, phase transformation accompanied by diffusion is not completely completed, and unreacted Ti-Al and the like are likely to be mixed in as impurities. Furthermore, because the arrangement of atoms within the crystal lattice of the intermetallic compound is disordered, the properties of the obtained intermetallic compound fell short of what was theoretically predicted.

(4) In conventional manufacturing methods, three processes are performed separately, and therefore large amounts of thermal energy, time, and cost are required for the production of titanium and aluminum, the production of alloy liquid, and the heat treatment required for homogenization treatment. This resulted in an expensive manufacturing method.

(Problems to be Solved by the Invention) By solving the above-mentioned problems, the present invention combines titanium (Ti) and aluminum, which are expected to be next-generation materials because of their high strength, heat resistance, corrosion resistance, and light weight. (
The present invention was an attempt to develop a mass production method for producing the intermetallic compound A ly Ti of A E ) with high purity and with less energy.

The present invention relates to a method for producing a large amount of AffisTi, which was invented by elucidating the details of the following production principles and optimal application conditions for each method. Specifically, (1) By blending titanium dioxide and aluminum oxide, which are oxides, titanium and aluminum become Al
(2) A first step in which an oxide mixture having a composition having a predetermined atomic fraction of Ti is prepared and titanium and aluminum atoms are blended as finely and uniformly as possible; (2) 1023 is added to this oxide mixture; ~1473
Calcium (Ca) or calcium hydride (CaH) under high temperature in the temperature range of K (750-1200'C)
(3) from the synthesized intermetallic compound Al3Ti, by-forming CaO and Ca-A42 alloy are dissolved and removed, and only the intermetallic compound AlzTi is purified. intermetallic compound A/2. T
This is a manufacturing method of t.

The present invention provides a method for producing an intermetallic compound Al 3 T f, which includes (1) fine mixing of Ti and Af atoms, (2) promotion of interdiffusion between Ti and /l atoms, and (3)
) AI! , 3 Ti crystal homogenization, (4) impurity removal, etc. As a result of synergistic effects, AI! We obtained a guideline that the synthesis of 3 Ti could be mass-produced at low cost, and as a result of intensive research, we came to invent a manufacturing method based on a combination of the above three steps.

In the manufacturing method of the present invention described above, in the first step, mixed titanium dioxide (TiO□) and aluminum oxide (A
It is important to grind the titanium and aluminum atoms of the titanium and aluminum atoms as finely as possible and thus to mix them homogeneously.

In the second step, this oxide mixture is heated to 1023 K to 147 K.
Calcium (Ca) or calcium hydride (CaH2) under high temperature in the temperature range of 3K (750℃~1200℃)
), and in this reduction process, oxygen bonded to titanium and aluminum atoms is released by Ca, and at the same time, the bond between Ti and An is promoted. As a result, a powdered intermetallic compound Al 3 Ti is synthesized together with calcium oxide (Cab) and a Ca-Af gold alloy.

In the third step, by-produced Cab and Ca--Al alloy are reduced and removed.

(Function) According to the present invention, the intermetallic compound Al 3 Ti of titanium and aluminum can be obtained in the form of powder or lumps with high purity, in mass production, and at low cost. By applying the single powder of the intermetallic compound Affi3Tt according to the present invention to a powder metallurgy method, a large sintered body close to a product shape that requires less cutting and welding can be formed, and can be directly incorporated into structures as various devices.

The sintered body can also be used as a target material for sputtering or vacuum evaporation, and can be used to perform surface treatments on various structures to improve their heat resistance and mechanical strength.

(Example) The method of the present invention will be explained based on the following example.

The method for producing Af 3 Ti according to the present invention uses titanium dioxide (T i O□) and aluminum oxide (A2□03) extracted from ores, scraps, etc. by various methods as starting materials. These are generally available in granular or powdered form and can be easily made into fine powder. These are weighed and mixed so that the molar ratio of Ti and A2 is 1/3) (or a value smaller than 1/3).This mixing ratio, together with the amount of reducing agent described later, will give a final value of about 6 molar ratios. Intermetallic compound A E
It affects the impurities contained in x T i.

Generally, the oxide mixture is obtained by thoroughly mixing in a mortar, ball mill, etc. When using granular or lumpy starting materials, mix and grind thoroughly to make a fine powder. In this way an oxide mixture is obtained.

In addition, as a method for obtaining the above-mentioned oxide mixture, the method for producing rTi and Al, for which some of the inventors have separately applied for a patent, is similar to the method for producing rTi and Al (Japanese Patent Application No. 435766/1999). ■
An oxide mixture can also be obtained by melting and mixing TiO□ and AfzCh and cooling. Also, it is also possible to mix oxides using an aqueous solution.

However, the method (■) requires high-temperature heating and is not economically preferable, and when the method (■) is used, the amount of aluminum hydroxide gel produced is larger than that in the production method of T i 3A 42. The large volume of the mixture caused many difficulties in dehydration. Therefore, it is considered economically desirable to use a mechanical oxide mixture that can be mixed in the simplest operation without the need for thermal energy or other reagents in the following steps.

The above oxide mixture was heated at 1023 K to 1473 K (
Calcium (Ca) or calcium hydride (Ca
Hz) to reduce it. The reason for using Ca or CaHz as the reducing agent here is to reduce Ti and Al, which have a particularly strong affinity for oxygen.

Therefore, in order to prevent the reducing agent from being consumed by oxygen in the air and moisture in the sample, and to prevent the formation of titanium nitrides by nitrogen, the reaction vessel containing the oxide mixture and reducing agent is , thoroughly degas and create a vacuum or introduce an inert gas. As described above, it is necessary to confine the oxide mixture and the reducing agent in a sealed container to prevent air from entering during the reaction at high temperatures, or to take measures to prevent air from entering.

Here, an example will be explained in which metallic calcium (Ca) is used as a reducing agent and a sealed container is used.

The chemical reaction inside the sealed container is as follows. 1023K
At ~1473 K (750°C ~ 1200°C), Ca becomes a liquid and generates vapor, and the saturated 1
I feel full of energy. This Ca vapor is Ti○2+A2□03
It acts on the mixed powder and reduces them to a Ti--Al alloy, which itself changes into solid calcium oxide (Cab) and deposits around the alloy particles. This can be expressed as a chemical reaction formula (1).

2TiOz +3AJhOz +13Ca (gas)
→[2Ti・6A 11+13CaO−(1) Alloy in the above chemical reaction, i.e. [2Ti・6Af
According to the analysis results of powder X-ray diffraction measurement, fil is A
12 z T i . That is, the formation reaction of a compound represented by the following formula is proceeding simultaneously with the above reduction reaction.

[2Ti・6Al)→2 A 13 T i ・・
・(2) However, when the reducing agent Ca is present in excess of the amount necessary for reduction, this Ca is converted into Ca A f! by the following chemical reaction. 2 may be produced as a by-product.

[2Ti・6Afl +Ca →2 A 422
T i + CaAl z −(3) or depending on the excess amount [2Ti ・6AA] +2 Ca →2 T iA
There is a possibility that side reactions such as It can also be a condition.

Compound Ca-Al. z or liquid Ca-A42 alloy can be removed by wet process step 1 described below, but at the same time it is difficult to remove intermetallic compounds such as Al 2 Ti and TiAl that are produced as by-products. For single-phase synthesis of 3T i powders, the side reactions mentioned above are undesirable. Therefore, the oxide mixture Ti/Af! It is most desirable in terms of material balance to strictly set the molar ratio of - to 1/3 and use only the equivalent amount of Ca required for reduction in the reactions (1) and (2) above.

The reaction described above utilizes Ca vapor.

The chemical reaction according to the present invention does not use the gaseous state of Ca, but
A solid state or a liquid state may be used. Alternatively, CaH2, which has a reducing effect similar to Ca, may be used. Ca
The chemical reaction formula when Hz is used as a reducing agent is shown below.

2 Ti0z+ 3 A 1zOy +13CaHz
−[2Ti ・6 A l) +13CaO+1
3H2-(5)[2Ti・6Afl I2 A A
x T i ... (6) Hydrogen gas (H2) generated by Ca HzO thermal decomposition cannot contribute to the reduction of Aff203 at all in thermodynamic theory, but T
It may partially contribute to the reduction of iO□. However, with only H2, even if the reaction proceeds theoretically, TiO□ is reduced only to Ti2O3, and titanium in a metallic state cannot be obtained. Further, a part of Ca Hz is thermally decomposed at the reduction temperature to become metallic calcium and exhibits a reducing action. Considering these two points, the above reaction formula (5), (6)%
Formula % Examples of synthetic reactions based on the above concept are shown below.

In order to carry out the reduction reaction completely, it is necessary and important to improve the airtightness of the reaction vessel containing the reducing agent and oxide mixture, and special attention must be paid to this.

In order to seal the container, it is common to exhaust the air and then isolate the stainless steel container from the outside air by joining such as welding, and this method can also be used for the present invention. However, in this method, the container must be destroyed in order to take out the sample inside the container after the reduction reaction is completed.

Therefore, for the purpose of reusing stainless steel containers, the reaction apparatus described in the above-mentioned Japanese Patent Application No. 1-235766 can be used in the present invention.

Place about 3.0 g of the oxide mixture on a molybdenum saucer,
Ca was isolated and placed in a stainless steel container so as not to come into direct contact with oxides. After replacing the atmosphere inside the stainless steel container with argon gas, heat the container to 750°C to 12°C.
The temperature was maintained at 00° C. for about 1 to 72 hours, and then cooled.

As a result of powder X-ray diffraction measurement, the powder obtained as a result of the above chemical reaction (reduction reaction) was found to be composed of the following substances. When calcium is used as a reducing agent, calcium oxide (Cab), Ca-Affi alloy, intermetallic compound A
13Ti, and unreacted calcium. In addition, when calcium hydride (Ca Hz) is used as a reducing agent, CaO, Ca--Al alloy, AlzTi,
and unreacted CaH2 and thermally decomposed metallic calcium.

Therefore, wet separation was performed in order to extract only the intermetallic compound A I23 Ti from the powder obtained by the above chemical reaction (reduction reaction).

The obtained powder was added to an acidic aqueous solution, and Cab, Ca-A
f Dissolving and separating gold alloy metal calcium and CaHz,
The compound was purified into powder and collected.

Here, as a wet separation reagent for purification, it is industrially effective to use water as a first-stage treatment to separate calcium metal, calcium hydride (CaH2), and calcium oxide (Cab). . However, since complete removal and purification is not possible with water alone, after rough wet separation with water is performed as the first stage treatment, the remaining residue is further removed as explained above as the second stage treatment. It is necessary to remove impurities. For this purpose, in addition to mineral acids, organic acids such as acetic acid and oxalic acid can also be used. Ca
In addition to the above-mentioned acidic aqueous solution, an ammonium chloride aqueous solution, an ammonium salt aqueous solution, a sucrose aqueous solution, etc. can be used to separate O. Generally, dilute aqueous solutions of mineral acids, such as hydrochloric acid, are economically preferred because they are readily available and inexpensive.

In addition, during wet separation for purification, mechanical stirring or ultrasonic vibration is applied to the aqueous solution, and further
Heating to 33 K) effectively performs purification, shortens wet separation time, and reduces contamination with impurities. When an inert gas such as argon gas is blown into the aqueous solution for purification, the amount of dissolved oxygen in the aqueous solution is reduced and the intermetallic compound A
Oxygen adhering to the 423 Ti powder is reduced, and a higher purity compound can be obtained. It is preferable that when a gas is blown into the aqueous solution during wet separation, the aqueous solution is stirred and purification can be carried out efficiently.

According to the concept of the above manufacturing method, T of the oxide mixture
The molar ratio of i/Af is set to 25/75 (-1I3),
Table 1 shows the results of powder X-ray diffraction measurements performed on powders that were purified by causing a reductive synthesis reaction with calcium hydride and using an acetic acid aqueous solution as a wet fraction M reagent. Table 1 shows that Ti is produced by calcium hydride (CaHz).
Sample powder
The names of substances contained in the sample are listed in the results of line diffraction measurements.

All of the starting oxides were reduced to a metallic state, and intermetallic compounds A l and T i were synthesized as shown in Table 1.

However, other intermetallic compounds existing in the Ti-Al system, such as A I Z Ti or TiA42, coexisted, and these impurities could not be removed by wet treatment. Furthermore, when washing was insufficient, the presence of CaAl□ was observed, although the amount was small. As shown in Table 1, even if the temperature and time of the reduction synthesis reaction were changed, the above-mentioned tendency did not change, and impurities were mixed in.

The causes of the above-mentioned impurity contamination will be described below.

In the case of the above production method, if even a small amount of reducing agent leaks from the reaction vessel during the reduction synthesis reaction, intermetallic compound A!
! , 3 Ti, and other impurities such as aluminum oxide and titanium oxide (TiO) were mixed. Therefore, in addition to the equivalent amount of reducing agent needed to reduce the starting sample, some extra amount of reducing agent was usually used as an oxygen scavenger in the reaction vessel. Furthermore, when calcium is used as a sealant for the reaction vessel, it also becomes an extra reducing agent for reduction. Although it is desirable to accurately estimate the amount of reducing agent leaking from the reaction vessel and inserting an equivalent amount of extra reducing agent, it is often difficult to evaluate the leaking amount.

Excess calcium is present in the reaction vessel, and the starting material T
When the molar ratio of i / Al is 1/3, excess calcium acts on the first synthesized A 123 T s, and 2 AfzTi + Ca → 2 AlzTi +
CaAlz・・・・・・ (7) Al+Ti +Ca −+TiAf+CaAnz −(
8) This is because the following reaction occurs. A I23 T i
It is difficult to remove the AlzTi 9TiA42 mixed in with the wet method, and the AlzTi 9TiA42 mixed in the
degrade the characteristics of i.

Al z Ti and TiA due to the side reactions mentioned above
j! To prevent contamination, take the following measures. That is, the molar ratio of T i /A l of the starting materials is made smaller than 1/3, and the amount of calcium component used in this production method is determined by the following formula.

A is the number of moles of metallic aluminum atoms contained in the starting oxide mixture, B is the number of moles of metallic titanium atoms contained in the starting oxide mixture, and is the number of moles of metallic calcium atoms that can act as a reducing agent in the reaction vessel. Let C be the number of moles.

A≧3B ・・・・・・・・・ (9)
C top 3/2A+2B ・・・・・・・・・ 00)C
≦2A+1/2B ・・・・・・・・・ 01)(9
) ~ (IIJ2) If the amount of metallic calcium contained in the reducing agent and sealing agent is adjusted, A
Ajl has more Ti content than f3Ti! zTi or Ti
-A l where intermetallic compounds such as Al are obtained in nature as impurities! It is not contained in Ti. Note that among the above equations, equation (9) is a condition for making the ratio of Ti and Af smaller than 1/3, and equation 00) is a condition for making the ratio of Ti and Af smaller than 1/3.
O2 and Af20. Formula 01) is the condition for reducing aluminum to metallic titanium and metallic aluminum, respectively, and the formula 01) is necessary for aluminum other than the aluminum atoms necessary for the synthesized A l :l Ti to exist as metallic aluminum or compound CaAlz. These are the conditions.

Controlling manufacturing conditions so as to satisfy the above three constraints is simple and highly practical.

The Ti/Af molar ratio of the oxide mixture is the theoretical amount of 25
/75 (= 1 /3), and during the reduction synthesis reaction,
The conditions to ensure that no reducing agent leaks from the reaction vessel are as follows:
(9) This corresponds to simultaneously establishing the equal sign in formula 2 and 00, and this condition is difficult in practice as described in section (4).

Table 2 shows the results of experiments conducted to examine the validity of the above three constraint conditions.

Table 2 shows that the oxide mixture was treated with calcium hydride (CaHz) at 1000°C (1273K) for 10.8ks.
The names of substances contained in the sample are listed based on the powder X-ray diffraction measurement results of the sample obtained by reducing and washing the obtained powder with an acetic acid aqueous solution.

Table 2 shows that the oxide mixture is reduced with calcium hydride,
This figure shows the results of powder X-ray diffraction measurements performed on powder washed with an aqueous acetic acid solution.

For all the samples shown in Table 2, an excess amount of calcium hydride was used in addition to an equivalent amount of calcium component necessary for reduction so as to satisfy the inequality of equation 00).

If the amount of the reducing agent is increased beyond the limit of formula 00, or if the amount of titanium atoms in the oxide mixture is increased beyond the limit of formula (9), A R, as shown in Table 2. z
A powder in which Ti or TiAf was mixed with Al 3 Ti was obtained. In particular, when the reaction time was increased, the amount of impurities tended to increase.

An example of operating the reductive synthesis reaction according to the present invention by adjusting the composition and amount of the oxide mixture and the amount of the reducing agent so as to satisfy all three constraint conditions is that T i /
The molar ratio of Al was 15/85, Ca Hz was used as a reducing agent, and 1008k was produced at 1000°C (1273K).
This is the case of s reaction.

The results of powder X-ray diffraction measurements on this sample are shown in the third
It is shown in Figure (a). FIG. 3(b) shows a reference pattern of the reported intermetallic compound A 1 3T i.

From FIG. 3(a), the measurement results of the powder produced by the production method of the present invention can be explained only by reference figures. Therefore, this sample is an intermetallic compound A j23T without any impurities.
It can be seen that it consists of a single i. The results of scanning electron microscope observation of this intermetallic compound A 1 :l Ti powder are shown in FIG.

It is a rounded powder with a size of several microns to over ten microns, and some of the particles are in contact with other particles.

Figure 5 summarizes the entire process explained above. This process will be explained in the order of steps as follows.

First step Homogeneous mixture of oxide powders Titanium dioxide (T i Oz ) and aluminum oxide (
AlzO3) is used as the starting material. These are weighed and thoroughly mixed in a mortar or ball mill to obtain a homogeneous oxide mixture. In addition to the process shown in Figure 5, this process involves 'Ti
The oxide powder homogeneous mixing process described in ``Method for Producing 3Af'' (Japanese Patent Application No. 1-235766) can be used. In either case, the composition is adjusted so that the relationship A≧3B is satisfied, where A is the number of moles of aluminum atoms in the oxide mixture, and B is the number of moles of titanium atoms in the oxide mixture.

2nd step This is a step in which the reduced oxide mixture is reduced with calcium or calcium hydride to obtain reduced powder. If the number of moles of metallic calcium, which is an active ingredient in the reducing agent, is C, then C is (3
/2) The reduction reaction will not be completed unless it is larger than A + 2B,
If C is not smaller than 2A+(1/2)B then A I! ,
AI such as z T i and T i A 1! , 3Ti, a compound serving as an impurity is produced as a by-product. The temperature of the reduction synthesis reaction is in the range of 750° C. to 1200° C. at which the reducing agent can act at a practically sufficient reaction rate.

3rd step: Wash the purified reduced powder with water, an aqueous ammonium chloride solution, or an acidic aqueous solution such as diluted hydrochloric acid.
High purity intermetallic compound A purified by dissolving and separating l-alloy, unreacted calcium, and calcium hydride 13
This is a process of obtaining powder of T i.

(Effects of the Invention) Various products incorporating the intermetallic compound A E 3 Ti according to the present invention are lightweight, have excellent heat resistance, corrosion resistance, and high mechanical strength, and are inexpensive. Intermetallic compound A l
3 Various products incorporating Ti, such as mechanical structural products that make up aircraft and spacecraft-related equipment, marine-related equipment such as deep-sea vessels, and transportation-related equipment such as magnetic levitation trains, jet engines, automobile engines, and generators. The invention is used in high-temperature power generation devices such as turbine blades used in industrial turbines, etc., and the present invention has the industrial advantage of being able to provide these at low cost.

[Brief explanation of the drawing]

Figure 1 is an alloy phase diagram of titanium and aluminum, and Figure 2 is a conventional intermetallic compound Af! A schematic diagram of the manufacturing process of 3Ti.
Powder X-ray diffraction measurement results (a) and intermetallic compound A I! of a sample obtained by washing the powder reduced with an acetic acid aqueous solution for 10.8 ks at 0°C (1273K) to remove impurities. ,
3 In the reference diagram (b) for Ti, Ti in the oxide mixture
The molar ratio of /Af is 15/85, and the X-ray used for the measurement is the α line of copper, and (b) is JCPDS card number 37.
-1449, Figure 4 shows the calculation of 10% by calcium hydride (CaHz).
The powder reduced at 00°C (1273K) for io, 8ks was washed with an acetic acid aqueous solution to reduce T i / in the oxide mixture.
Intermetallic compound A from which impurities have been removed, the molar ratio of Al being 15/85 1. A scanning electron micrograph of ffTi, FIG. 5 is a schematic diagram showing the manufacturing method of the present invention. ■...Range 2 where intermetallic compound T i A l exists
...Range 3 where intermetallic compound AlsTi exists...
Range where alloy liquid exists 4... Range where intermetallic compound T i :+A, 12 exists 5... Range where β Ti exists 6... Range where α-Ti exists

Claims (1)

[Claims] 1. Titanium dioxide (TiO_2) and aluminum oxide (Al_2O_3), which are oxides, are mixed so that the composition of Ti and Al becomes the composition of the intermetallic compound Al_3Ti, or the composition contains more aluminum than that. The first step is to uniformly mix titanium and aluminum atoms into as fine a powder as possible in the oxide mixture blended and mixed in the following manner; Calcium (Ca) or calcium hydride (C
aH_2) to reduce the amount of carbon by-formed from the synthesized intermetallic compound Al_3Ti.
aO and CaAl_2 or Ca-Al alloy with water,
Alternatively, the intermetallic compound Al_3T can be dissolved and removed with any solvent selected from acidic aqueous solution and ammonium chloride aqueous solution.
A method for producing an intermetallic compound Al_3Ti, comprising a third step of purely extracting only i.