JP2017186609A - TiAl-BASED INTERMETALLIC COMPOUND SINTERED BODY AND MANUFACTURING METHOD OF TiAl-BASED INTERMETALLIC COMPOUND SINTERED BODY - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance sinter density of a TiAl-based intermetallic compound sintered body.SOLUTION: A manufacturing method of a TiAl-based intermetallic compound sintered body produces the TiAl-based intermetallic compound sintered body by sintering a TiAl-based powder containing a TiAl-based intermetallic compound where Ti and Al bind and an added metal. The added metal is Ni or Ni and Fe.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a TiAl-based intermetallic compound sintered body and a method for producing a TiAl-based intermetallic compound sintered body.

  TiAl-based intermetallic compounds are intermetallic compounds (alloys) composed of Ti (titanium) and Al (aluminum) bonded together, and are lightweight and have high strength at high temperatures. Applied to high temperature structural materials. TiAl-based intermetallic compounds are difficult to form by forging, casting, or the like due to their low spreadability, and may be formed by sintering. A sintered body of a TiAl-based intermetallic compound is formed, for example, by sintering a powder of a TiAl-based intermetallic compound as shown in Patent Document 1.

Japanese Patent Laid-Open No. 3-243741

  The sintered body of the TiAl-based intermetallic compound can have higher strength by increasing the sintered density when sintered. Therefore, higher sintering density is required.

  Accordingly, the present invention provides a TiAl-based intermetallic compound sintered body having a high sintered density and high strength, and a method for producing a TiAl-based intermetallic compound sintered body having a high sintered density and high strength. Objective.

  In order to solve the above-described problems and achieve the object, a manufacturing method of a TiAl-based intermetallic compound sintered body according to the present disclosure includes a TiAl-based intermetallic compound in which Ti and Al are bonded, and an additive metal. A sintered powder body is sintered to produce a TiAl intermetallic compound sintered body, and the additive metal is Ni or Ni and Fe. In this method of manufacturing a TiAl-based intermetallic compound sintered body, the TiAl-based intermetallic compound sintered body can be made into a metal structure in which an additive metal phase is present at the grain boundary of the adjacent TiAl phase. Therefore, this method for producing a TiAl-based intermetallic compound sintered body can increase the sintered density and the strength.

  The method of manufacturing the TiAl-based intermetallic compound sintered body includes a mixing step of mixing the TiAl-based powder body and a binder to obtain a mixture, and injection molding in which the mixture is formed into a molded body by a metal injection molding machine. It is preferable to include a step, a degreasing step for degreasing the molded body to produce a degreased body, and a sintering step for sintering the degreased body to produce the TiAl-based intermetallic compound sintered body. Since this TiAl-based intermetallic compound sintered body uses a metal powder injection molding method, it is possible to improve the shape accuracy while improving the sintering density.

  In the method for producing a TiAl-based intermetallic compound sintered body, the TiAl-based powder body preferably has a Ni content of 0.01 wt% or more and 1 wt% or less. In this method of manufacturing a TiAl-based intermetallic compound sintered body, the additive metal phase can be appropriately present at the grain boundary of the adjacent TiAl phase, so that the sintered density can be appropriately improved.

  In the method for producing a TiAl-based intermetallic compound sintered body, the TiAl-based powder body preferably has a total amount of Ni and Fe of 0.01% by weight or more and 2% by weight or less. In this method of manufacturing a TiAl-based intermetallic compound sintered body, the additive metal phase can be appropriately present at the grain boundary of the adjacent TiAl phase, so that the sintered density can be appropriately improved.

  In the method for manufacturing a TiAl-based intermetallic compound sintered body, the TiAl-based powder body is preferably a mixture of a plurality of TiAl-based solid solution powders containing the TiAl-based intermetallic compound and the additive metal. . In this method of manufacturing a TiAl-based intermetallic compound sintered body, the additive metal phase can be appropriately present at the grain boundary of the adjacent TiAl phase, so that the sintered density can be appropriately improved.

  In the method for manufacturing a TiAl-based intermetallic compound sintered body, the TiAl-based powder body is a mixture of a TiAl-based powder that is a powder of the TiAl-based intermetallic compound and an additive metal powder containing the additive metal. It is preferable. In this method of manufacturing a TiAl-based intermetallic compound sintered body, the additive metal phase can be appropriately present at the grain boundary of the adjacent TiAl phase, so that the sintered density can be appropriately improved.

  In order to solve the above-described problems and achieve the object, the TiAl-based intermetallic compound sintered body of the present disclosure contains a TiAl-based intermetallic compound in which Ti and Al are bonded, and an additive metal that is Ni, The Ni content is 0.01% by weight or more and 1% by weight or less of the whole. Since this TiAl-based intermetallic compound sintered body contains Ni in this compounding ratio with respect to the TiAl-based intermetallic compound, it is possible for the Ni phase to exist at the grain boundary of the TiAl phase of the sintered body. Become. Therefore, the sintered density of the TiAl-based intermetallic compound sintered body is improved.

  In order to solve the above-described problems and achieve the object, a TiAl-based intermetallic compound sintered body of the present disclosure includes a TiAl-based intermetallic compound in which Ti and Al are bonded, and an additive metal that is Ni and Fe. The total content of Ni and Fe is 0.01% by weight or more and 2% by weight or less based on the total content. Since this TiAl-based intermetallic compound sintered body contains Ni and Fe in this compounding ratio with respect to the TiAl-based intermetallic compound, the NiFe phase must exist at the grain boundary of the TiAl phase of the sintered body. Is possible. Therefore, the sintered density of the TiAl-based intermetallic compound sintered body is improved.

  In the TiAl-based intermetallic compound sintered body, the TiAl-based intermetallic compound contains 20 to 80 wt% Ti, 20 to 80 wt% Al, and 0 to 30 wt% mixed metal, The mixed metal preferably contains at least one of Nb, Cr, and Mn. The TiAl-based intermetallic compound sintered body has improved strength because the TiAl-based intermetallic compound has this blending ratio.

  In the TiAl-based intermetallic compound sintered body, a plurality of TiAl-based sintered powders containing the TiAl-based intermetallic compound and the additive metal are bonded, and the additive metal phase that is a metal phase of the additive metal is It is preferable that it exists between the adjacent TiAl-based sintered powders. In this TiAl-based intermetallic compound sintered body, since the additive metal phase is present at the grain boundary of the TiAl phase of the sintered body, the sintering density is more appropriately improved.

  According to the present invention, the sintered density of the TiAl-based intermetallic compound sintered body can be increased and the strength can be increased.

FIG. 1 is a block diagram showing a configuration of a sintered body manufacturing system according to the first embodiment. FIG. 2 is an explanatory diagram schematically illustrating the configuration of the powder manufacturing apparatus according to the first embodiment. FIG. 3 is a schematic view for explaining phases of the TiAl-based intermetallic compound sintered body according to the first embodiment. FIG. 4 is a flowchart for explaining a manufacturing flow of the TiAl-based intermetallic compound sintered body by the sintered body manufacturing system according to the first embodiment. FIG. 5 is a table showing the sintered density of the example and the comparative example. FIG. 6 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the comparative example. FIG. 7 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the comparative example. FIG. 8 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the example. FIG. 9 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the example. FIG. 10 is a graph showing the relationship between the Ni content and the sintered density. FIG. 11 is a table showing the sintered density of the example and the comparative example. FIG. 12 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the comparative example. FIG. 13 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the example. FIG. 14 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the example. FIG. 15 is a graph showing the relationship between the Ni and Fe contents and the sintered density. FIG. 16 is a table showing the sintered density of the example and the comparative example. FIG. 17 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the comparative example. FIG. 18 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, Moreover, when there are two or more embodiments, what comprises a combination of each Example is also included.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of a sintered body manufacturing system according to the first embodiment. A sintered body manufacturing system 1 according to the first embodiment is a system for executing a method of manufacturing a sintered body of a TiAl-based intermetallic compound. The TiAl-based intermetallic compound sintered body is a sintered body mainly composed of a TiAl-based intermetallic compound (TiAl-based alloy). The TiAl-based intermetallic compound in the present embodiment is a compound in which Ti (titanium) and Al (aluminum) are bonded (TiAl, Ti ₃ Al, Al ₃ Ti, etc.). However, the TiAl-based intermetallic compound may be a solution in which a mixed metal M described later is dissolved in a TiAl phase that is a phase in which Ti and Al are bonded.

  As shown in FIG. 1, the sintered body manufacturing system 1 includes a powder manufacturing apparatus 10, a metal powder injection molding apparatus 20, a degreasing apparatus 30, and a sintering apparatus 40. The sintered body manufacturing system 1 manufactures powder of TiAl-based intermetallic compound with a powder manufacturing apparatus 10, and metal powder injection molding with a binder by a metal powder injection molding apparatus 20, and metal powder injection with a sintering apparatus 40. The formed compact is sintered to produce a TiAl-based intermetallic compound sintered body (TiAl-based intermetallic compound sintered body).

The powder production apparatus 10 produces a TiAl-based solid solution powder B ₁ from a TiAl-based ingot A ₁ . TiAl-based ingot A ₁ is an ingot of the above-described TiAl-based intermetallic compound. In the present embodiment, the TiAl-based ingot A ₁ is obtained by dissolving an additive metal in the TiAl phase of a TiAl-based intermetallic compound. The additive metal in the first embodiment is Ni (nickel). TiAl-based ingot A ₁ has a TiAl-based intermetallic compound content of 99 wt% or more and 99.99 wt% or less, and the content of Ni as an additive metal is 0.01 wt% or more and 1 wt% or less. It is. Further, the content of Ni as the additive metal is more preferably 0.2 wt% or more and 0.6 wt% or less.

The TiAl-based intermetallic compound in the TiAl-based ingot A ₁ contains 20 to 80 wt% Ti, 20 to 80 wt% Al, and 0 to 30 wt% mixed metal M. That is, the TiAl-based ingot A ₁ has a Ti content of 19.8 wt% or more and 79.992 wt% or less, and an Al content of 19.8 wt% or more and 79.992 wt% when viewed from all components including the added metal. The mixed metal M is 0 wt% or more and 29.997 wt% or less. When the TiAl-based intermetallic compound in the TiAl-based ingot A ₁ contains the mixed metal M, the mixed metal M is in the form of a solid solution in the TiAl phase. The mixed metal M is a metal other than Ti and Al, and contains at least one of Nb (niobium), Cr (chromium), and Mn (manganese), for example.

As described above, the TiAl-based ingot A ₁ is an alloy lump in which Ni as an additive metal and mixed metal M are dissolved in the TiAl phase of the TiAl-based intermetallic compound. The TiAl-based ingot A ₁ is manufactured by melting and mixing pure metals (Ti, Al, Ni, mixed metal M) of each component and then cooling.

FIG. 2 is an explanatory diagram schematically illustrating the configuration of the powder manufacturing apparatus according to the first embodiment. As shown in FIG. 2, the powder manufacturing apparatus 10 includes a heating body 12 and a gas injection body 14. Heating body 12 is a heating wire that is coiled around the TiAl-based ingot A _1. Heating body 12 generates heat when current flows, melting the TiAl-based ingot _{A 1.} The molten TiAl-based ingot A ₁ is dropped as a liquid TiAl-based melt A _{2 in} the vertical direction below the TiAl-based ingot A ₁ .

The gas injection body 14 is an injection tube that allows an inert gas G (argon in the present embodiment) to flow inside and injects the inert gas G from an opening. Opening of the gas injection member 14, with respect to TiAl-based ingot _A is located vertically below the _1, TiAl-based ingot _A TiAl-based melt _{A 2} dripped downward in the vertical direction of _1, inert gas G is injected. The TiAl-based melt A ₂ to which the inert gas G has been injected is cooled and solidified while being divided into a plurality of pieces, and becomes a plurality of TiAl-based solid solution powders B ₁ . In addition, in this embodiment, although the gas injection body 14 is plural, the number may be single and the number is arbitrary.

Since the TiAl-based solid solution powder B ₁ is manufactured by melting and solidifying the TiAl-based ingot A ₁ , the contained metal component is the same as that of the TiAl-based ingot A ₁ . That, TiAl-based solid solution powder _{B 1} represents an alloy powder Ni and mixed metal M as an additive metal TiAl phase is a solid solution of TiAl-based intermetallic compound (particles). Then, TiAl-based solid solution powder _{B 1} represents the content ratio of the metal components is the same as the TiAl-based ingot _{A 1.} The particle size of the TiAl-based solid solution powder _{B 1} represents, 1 [mu] m or more 50μm or less, more preferably 1 [mu] m or more 20μm or less. In the description of this embodiment, one powder (one particle) is described as a powder, and an aggregate of a plurality of powders is described as a powder body. TiAl based solid solution powder _{B 1} represents a single powder (particle), a plurality of the aggregate of TiAl-based solid solution powder _{B 1,} referred to as TiAl-based powder material _{B 2.}

A metal powder injection molding apparatus 20 shown in FIG. 1 is an apparatus that performs metal powder injection molding (MIM). The metal powder injection molding apparatus 20 manufactures a molded body D from the mixture C. The mixture C is a mixture of the TiAl-based powder B ₂ manufactured by the powder manufacturing apparatus 10 and a binder. The binder is for joining the TiAl-based solid solution powder _{B 1} between the TiAl-based powder body _{B 2} is a resin having fluidity. The mixture C is provided with fluidity and moldability by adding a binder.

  The metal powder injection molding apparatus 20 injects the mixture C into a mold. The mixture C injected into the mold forms a molded body D. Since the molded body D is provided with fluidity by adding a binder, the molded body D is maintained in a shape defined by the mold even when it is removed from the mold.

  The degreasing device 30 is a device for degreasing the molded body D. Specifically, the degreasing apparatus 30 accommodates the molded body D taken out from the mold and heats the interior to a degreasing temperature, thereby removing (degreasing) the binder from the molded body D, and degreasing A field E is generated. The degreasing temperature is a temperature equal to or higher than the temperature at which the binder is thermally decomposed.

Sintering device 40 houses a degreased body E therein, sintered by heating the interior sintering temperature, the brown body E sintering (a TiAl-based solid solution powder B ₁ together in degreased body E ) To produce a TiAl-based intermetallic compound sintered body F. The sintering temperature is a temperature at which the TiAl-based solid solution powders B ₁ can be sintered with each other, for example, between 1400 ° C. and 1500 ° C. The sintering apparatus 40 promotes sintering by maintaining the inside at a sintering temperature for a predetermined time (for example, 1 hour). The sintering device 40 may be a device different from the degreasing device 30 or the same device as the degreasing device 30. When the sintering apparatus 40 is the same apparatus as the degreasing apparatus 30, the temperature is continuously raised to the sintering temperature without decreasing the temperature from the degreasing temperature.

TiAl-based intermetallic compound sintered body F is for the TiAl-based solid solution powder B ₁ together in degreased body E is obtained by sintering, the same components as TiAl-based solid solution powder B _1, containing only the same ratio . That is, in the TiAl-based intermetallic compound sintered body F, the content of the TiAl-based intermetallic compound is 99% by weight or more and 99.99% by weight or less, and the content of Ni as the additive metal is 0.01% by weight. % To 1% by weight. Further, the content of Ni as the additive metal is more preferably 0.2 wt% or more and 0.6 wt% or less. Further, the TiAl-based intermetallic compound in the TiAl-based intermetallic compound sintered body F contains 20 to 80 wt% Ti, 20 to 80 wt% Al, and 0 to 30 wt% mixed metal M. To do. That is, in the TiAl-based intermetallic compound sintered body F, Ti is 19.8% by weight or more and 79.992% by weight or less and Al is 19.8% by weight or more when viewed from all the components including the added metal. 79.992% by weight or less, and the mixed metal M is 0% by weight or more and 29.997% by weight or less.

Here, the TiAl-based solid solution powder _{B 1} joined by sintering, and TiAl based sintered powder F1. The TiAl-based intermetallic compound sintered body F is obtained by bonding (welding) a plurality of TiAl-based sintered powders F1 by forming a neck. TiAl based solid solution powder _{B 1} represents, in TiAl-based intermetallic the compound (TiAl Aiuchi), Ni as an additive metal is solid-solved. On the other hand, in the TiAl-based sintered powder F1, Ni as the additive metal is not dissolved in the TiAl-based intermetallic compound (in the TiAl phase), and the phase is divided into the TiAl phase and the additive metal phase (Ni phase). Are separated. In other words, the TiAl-based intermetallic compound (TiAl phase) in the TiAl-based intermetallic compound sintered body F contains Ti, Al, and the mixed metal M, and does not contain Ni.

  FIG. 3 is a schematic view for explaining phases of the TiAl-based intermetallic compound sintered body according to the first embodiment. Hereinafter, the TiAl phase in the TiAl-based sintered powder F1 is referred to as TiAl phase F2, and the additive metal phase (Ni phase) is referred to as additive metal phase F3. As shown in FIG. 3, the Ni phase (added metal phase F3) is between adjacent TiAl-based sintered powders F1 (grain boundaries), that is, TiAl phase F2 of one TiAl-based sintered powder F1 and adjacent thereto. Between the TiAl phase F2 of the TiAl-based sintered powder F1. Furthermore, the Ni phase (added metal phase F3) exists around each of the plurality of TiAl-based intermetallic compounds (TiAl phase F2).

  In the TiAl-based intermetallic compound sintered body F, since the additive metal phase F3 is present at the grain boundary between the adjacent TiAl phases F2, the sintered density is improved.

Hereinafter, a manufacturing flow of the TiAl-based intermetallic compound sintered body F by the sintered body manufacturing system 1 will be described. FIG. 4 is a flowchart for explaining a manufacturing flow of the TiAl-based intermetallic compound sintered body by the sintered body manufacturing system according to the first embodiment. As shown in FIG. 4, the sintered body manufacturing system 1 first generates a plurality of TiAl-based solid solution powders B ₁ (TiAl-based powder bodies B ₂ ) from the TiAl-based ingot A ₁ by the powder manufacturing apparatus 10. (Step S10). After generating the TiAl-based solid solution powder _{B 1,} the sintered body manufacturing system 1 generates a mixture C by mixing a TiAl-based powder body _{B 2} and a binder (step S12), the metal powder injection molding device 20 Thus, the mixture C is injection molded to form the molded body D (step S14). After molding the molded body D, the sintered body manufacturing system 1 generates the degreased body E by degreasing the molded body D by the degreasing apparatus 30 (step S16), and sinters the degreased body E by the sintering apparatus 40. Then, a TiAl-based intermetallic compound sintered body F is generated (step S18). By Step S18, the manufacturing process of the TiAl-based intermetallic compound sintered body is completed.

As explained above, the manufacturing method of the TiAl-based intermetallic compound sintered body F executed by the sintered body manufacturing system 1 according to the present embodiment sinters the TiAl-based powder body B ₂ to obtain the TiAl-based intermetallic compound. A sintered body F is produced. TiAl based powder body _{B 2} contains the additive metal and TiAl-based intermetallic compound Ti and Al are bonded. The additive metal is Ni in the first embodiment. The method for producing the TiAl-based intermetallic compound sintered body F sinters the TiAl-based powder body B ₂ containing the TiAl-based intermetallic compound and the additive metal. A metal structure in which the additive metal phase F3 exists at the grain boundary of the adjacent TiAl phase F2 can be obtained. Therefore, the manufacturing method of this TiAl-based intermetallic compound sintered body F can increase the sintering density and the strength.

The manufacturing method of the TiAl-based intermetallic compound sintered body F executed by the sintered body manufacturing system 1 includes a mixing step, an injection molding step, a degreasing step, and a sintering step. Mixing step to obtain a mixture C by mixing a TiAl-based powder body B ₂ and a binder. In the injection molding step, the mixture C is formed into a molded body D by a metal powder injection molding machine (metal powder injection molding apparatus 20). In the degreasing step, the molded body D is degreased to produce a degreased body E. In the sintering step, the degreased body E is sintered to produce a TiAl-based intermetallic compound sintered body F. The manufacturing method of this TiAl type intermetallic compound sintered body F manufactures the TiAl type intermetallic compound sintered body F using a metal powder injection molding method. When using the metal powder injection molding method, it is necessary to sinter while maintaining the molded shape. In particular, when a sintered body of TiAl-based intermetallic compound is produced by a metal powder injection molding method, the sintering conditions for sintering while maintaining the molded shape are severe, such as a narrow sintering temperature range. ing. Therefore, when producing a sintered body of TiAl-based intermetallic compound by the metal powder injection molding method, the sintering conditions cannot be set appropriately, and it may be difficult to improve the sintered density while maintaining the molded shape. There is. However, according to the present embodiment, the TiAl-based intermetallic compound sintered body F can have a metal structure in which the additive metal phase F3 exists at the grain boundary of the adjacent TiAl phase F2. Therefore, the manufacturing method of the TiAl-based intermetallic compound sintered body F can improve the shape accuracy by the metal powder injection molding method while keeping the sintered density high.

TiAl based powder body _{B 2,} the content of Ni is 1 wt% or less than 0.01 wt%. As a result, the sintering apparatus 40 can appropriately cause the additive metal phase F3 to exist at the grain boundary of the adjacent TiAl phase F2. Therefore, the manufacturing method of this TiAl-based intermetallic compound sintered body F can improve the sintering density more appropriately.

Further, TiAl-based powder block _{B 2} is obtained by mixing a plurality of TiAl-based solid solution powder _{B 1} containing the additive metal and TiAl-based intermetallic compound. The TiAl-based intermetallic compound sintered body F is manufactured by using a TiAl-based solid solution powder B ₁ used for sintering as a powder containing a TiAl-based intermetallic compound and an additive metal, so that TiAl of the sintered body is obtained. The added metal phase F3 can be appropriately present at the grain boundary of the phase F2. Therefore, the manufacturing method of this TiAl-based intermetallic compound sintered body F can improve the sintering density more appropriately.

  The TiAl-based intermetallic compound sintered body F according to the present embodiment includes a TiAl-based intermetallic compound in which Ti and Al are bonded and an additive metal that is Ni, and the content of Ni is 0.01 wt. % To 1% by weight. Since this TiAl-based intermetallic compound sintered body F contains Ni in this compounding ratio with respect to the TiAl-based intermetallic compound, the additive metal phase F3 is present at the grain boundary of the TiAl phase F2 of the sintered body. It becomes possible. Therefore, this TiAl-based intermetallic compound sintered body F can improve the sintering density more appropriately.

  In the TiAl-based intermetallic compound sintered body F, the TiAl-based intermetallic compound contains 20 to 80 wt% Ti, 20 to 80 wt% Al, and 0 to 30 wt% mixed metal M, The mixed metal M contains at least one of Nb, Cr, and Mn. The TiAl-based intermetallic compound sintered body F has improved strength because the TiAl-based intermetallic compound has this blending ratio.

  In the TiAl-based intermetallic compound sintered body F, a plurality of TiAl-based sintered powders F1 containing a TiAl-based intermetallic compound and an additive metal are bonded, and the additive metal phase that is the metal phase of the additive metal is adjacent to the TiAl-based intermetallic compound sintered body F. Between the TiAl-based sintered powder F1. In this TiAl-based intermetallic compound sintered body F, since the additive metal phase F3 is present at the grain boundary of the TiAl phase F2 of the sintered body, the sintered density can be improved more appropriately.

(Second Embodiment)
Next, a second embodiment will be described. The second embodiment is different from the first embodiment in that Ni and Fe (iron) are used as additive metals. In the second embodiment, description of portions having the same configuration as that of the first embodiment is omitted.

The additive metals according to the second embodiment are Ni and Fe. In the TiAl-based ingot A _{1 according} to the second embodiment, the content of the TiAl-based intermetallic compound is 98 wt% or more and 99.99 wt% or less, and the total content of Ni and Fe as additive metals is 0. 0.01% by weight or more and 2% by weight or less. Further, Ni is contained in an amount of 0.01% by weight or more and less than 2% by weight, and more preferably 0.01% by weight or more and 1% by weight or less with respect to the total amount of Ni and Fe.

In the second embodiment, a TiAl-based intermetallic compound sintered body F is generated by the same method as in the first embodiment, using this TiAl-based ingot A ₁ containing Ni and Fe as additive metals. In the TiAl-based intermetallic compound sintered body F according to the second embodiment, the content of the TiAl-based intermetallic compound is 98 wt% or more and 99.99 wt% or less, and the total content of Ni and Fe is 0. 0.01% by weight or more and 2% by weight or less.

  The TiAl-based intermetallic compound sintered body F according to the second embodiment forms the same phase as in the first embodiment. That is, in the TiAl-based intermetallic compound sintered body F according to the second embodiment, the alloy phase of Ni and Fe (added metal phase F3) is between adjacent TiAl-based sintered powders F1 (grain boundaries), that is, It exists between the TiAl phase F2 of one TiAl-based sintered powder F1 and the TiAl phase F2 of the TiAl-based sintered powder F1 adjacent thereto. Accordingly, the sintered density of the TiAl-based intermetallic compound sintered body F according to the second embodiment is also improved because the added metal phase F3 is present at the grain boundary between the adjacent TiAl phases F2.

In the TiAl-based powder body B _{2 according} to the second embodiment, the total content of Ni and Fe is 0.01 wt% or more and 2 wt% or less. As a result, the sintering apparatus 40 can appropriately cause the additive metal phase F3 to exist at the grain boundary of the adjacent TiAl phase F2. Therefore, the manufacturing method of the TiAl-based intermetallic compound sintered body F according to the second embodiment can also improve the sintering density more appropriately.

  The TiAl-based intermetallic compound sintered body F according to the second embodiment includes a TiAl-based intermetallic compound in which Ti and Al are combined, and an additive metal that is Fe and Ni, and the total content of Fe and Ni is The total content is 0.01% by weight or more and 2% by weight or less. Since this TiAl-based intermetallic compound sintered body F contains Fe and Ni in this compounding ratio with respect to the TiAl-based intermetallic compound, the additive metal phase F3 is added to the grain boundary of the TiAl phase F2 of the sintered body. It becomes possible to exist. Therefore, this TiAl-based intermetallic compound sintered body F can improve the sintering density more appropriately.

  As shown in the first and second embodiments, the sintering density of the TiAl-based intermetallic compound sintered body F can be improved more appropriately by using Ni or Ni and Fe as the additive metal. Can do.

(Third embodiment)
Next, a third embodiment will be described. In the third embodiment, as the TiAl-based powder body, a mixture of a TiAl-based powder which is a powder of a TiAl-based intermetallic compound and an additive metal powder containing Ni as an additive metal is used. Different from the embodiment. In the third embodiment, description of portions having the same configuration as that of the first embodiment is omitted.

The powder manufacturing apparatus 10 according to the third embodiment manufactures a TiAl-based powder B ₁ a from a TiAl-based ingot A ₁ a. TiAl-based ingot A ₁ a does not contain Ni as an additive metal, but contains only a TiAl-based intermetallic compound. The TiAl-based intermetallic compound here is Ti, Al, and mixed metal M as in the first embodiment, and the blending ratio is the same as in the first embodiment. The TiAl-based powder B ₁ a is a powder containing Ti, Al, and a mixed metal M, and has the same content ratio as the TiAl-based ingot A ₁ a. The particle size of the TiAl-based powder _{B 1} a is the same as TiAl-based solid solution powder _{B 1} of the first embodiment.

In the third embodiment, a plurality of TiAl-based powders B ₁ a and a plurality of additive metal powders B ₃ a are mixed to produce a TiAl-based powder body B ₂ a. The additive metal powder B ₃ a is a Ni powder. That is, the TiAl-based powder body B ₂ a has powders of two different components, that is, a TiAl-based intermetallic compound powder and a Ni powder that is an additive metal powder. In the TiAl-based powder body B ₂ a, the content ratio of the TiAl-based intermetallic compound and Ni is the same as that of the TiAl-based powder body B _{2 according} to the first embodiment.

The particle size of the added metal powder _{B 3} a is the same range as TiAl-based powder _{B 1} a, and more preferably less than TiAl-based powder _{B 1} a. For example, the particle size of the additive metal powder B ₃ a is preferably 0.01 times or more and 0.2 times or less that of the TiAl-based powder B ₁ a.

The sintered body manufacturing system 1 according to the third embodiment generates the mixture C by mixing the TiAl-based powder body B _2a and the binder, and thereafter the sintered body manufacturing system 1 according to the third embodiment. The process is the same as in the first embodiment, and the same TiAl-based intermetallic compound sintered body F as in the first embodiment is manufactured.

As described above, the TiAl-based powder body B ₂ a according to the third embodiment includes a TiAl-based powder B ₁ a that is a powder of a TiAl-based intermetallic compound, an additive metal powder B ₃ a that contains Ni as an additive metal, and A mixture of a plurality of Even in such a case, the same TiAl-based intermetallic compound sintered body F as in the first embodiment can be manufactured. Therefore, the sintered body manufacturing system 1 according to the third embodiment is the first embodiment. Similar to the form, the sintered density can be appropriately improved.

The manufacturing method according to the third embodiment can also be applied to the second embodiment. That is, the additive metal powder B ₃ a may be Ni and Fe powder. In this case, the additive metal powder B ₃ a may be Ni powder and Fe powder, or may be an alloy powder of Ni and Fe. In this case, the TiAl-based powder body B ₂ a has the same content ratio of the TiAl-based intermetallic compound to Ni and Fe as the TiAl-based powder body B _{2 according} to the second embodiment. Further, the additive metal powder body B ₂ a has the same content ratio of Ni and Fe as in the first embodiment.

  In the above description, the additive metal is Ni, or Ni and Fe. However, even if the additive metal is only Fe, if the Fe content is 2% by weight or more, the sintered density is similarly reduced. Can be high. In this case, the content of Fe is preferably 5% by weight or less in order to suppress a decrease in strength (creep strength) of the sintered body and a decrease in oxidation resistance.

(Example)
Next, examples will be described. FIG. 5 is a table showing the sintered density of the example and the comparative example. 6 and 7 are diagrams of the metal structure of the TiAl-based intermetallic compound sintered body of the comparative example. 8 and 9 are diagrams of the metal structure of the TiAl-based intermetallic compound sintered body of the example. FIG. 10 is a graph showing the relationship between the Ni content and the sintered density. In each example described below, a compact formed by a metal powder injection molding machine was degreased and then sintered at a sintering temperature of 1450 ° C. for 2 hours to produce a TiAl-based intermetallic compound sintered body F. In each comparative example to be described below, a compact formed by a metal powder injection molding machine is degreased in the same manner as in the examples, and then sintered at a sintering temperature of 1450 ° C. for 2 hours to obtain a TiAl-based intermetallic compound sintered body Fx. Manufactured. The TiAl-based intermetallic compound sintered body F according to each example includes 30% by weight of Al, 14% by weight of Nb as the mixed metal M, and 0.7% by weight of Cr as the mixed metal M, The same applies to the TiAl-based intermetallic compound sintered body Fx according to each comparative example.

The TiAl-based intermetallic compound sintered body Fx according to Comparative Example 1 does not contain both Fe and Ni. More specifically, in the TiAl-based intermetallic compound sintered body Fx according to Comparative Example 1, the Fe content is less than 0.05% by weight and the Ni content is less than 0.01% by weight. Further, as shown in FIG. 5, the TiAl-based intermetallic compound sintered body Fx according to Comparative Example 2 has a Fe content of less than 0.05% by weight and a Ni content of 1.05% by weight. . As shown in FIG. 5, the TiAl-based intermetallic compound sintered body F according to Example 1 contains only Ni as an additive metal, and the content of Ni is 0.2% by weight of the whole, The Fe content is less than 0.05% by weight. The TiAl-based intermetallic compound sintered body F according to Example 2 contains only Ni as an additive metal, the Ni content is 0.6% by weight, and the Fe content is the whole. Of 0.05% by weight or less. In Comparative Example 1 and Examples 1 and 2, the method of the third embodiment, that is, the manufacturing method of mixing TiAl-based powder B ₁ a and additive metal powder B ₃ a was applied.

  The TiAl-based intermetallic compound sintered body Fx according to Comparative Example 1 has a sintered density of 91% as shown in FIG. 5 and a large number of pores V as shown in FIG. As shown in FIG. 5, the TiAl-based intermetallic compound sintered body Fx according to Comparative Example 2 has a sintered density of 97%, and as shown in FIG. Colonies of A γ-phase colony is a lump of a γ-phase, and deteriorates the performance of a TiAl-based intermetallic compound sintered body having a lamellar structure.

  On the other hand, the TiAl-based intermetallic compound sintered body F according to Example 1 has a sintered density of 98%, as shown in FIG. 5, has a small number of pores V, and has a γ phase as shown in FIG. No colony has been generated. As shown in FIG. 5, the sintered TiAl-based intermetallic compound F according to Example 2 has a sintered density of 97%, and as shown in FIG. 9, there are few voids V and γ-phase colonies. Neither has occurred.

  The horizontal axis in FIG. 10 is the Ni content, and the vertical axis is the sintered density. FIG. 10 is a plot of the results of Comparative Examples 1 and 2 and Examples 1 and 2. As shown in FIG. 10, the TiAl-based intermetallic compound sintered body F containing only Ni as an additive metal has a high sintering density when Ni is contained in an amount of 0.1 wt% or more and 1 wt% or less, Generation of γ-phase colonies can be suppressed.

  FIG. 11 is a table showing the sintered density of the example and the comparative example. FIG. 12 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the comparative example. 13 and 14 are diagrams of the metal structure of the TiAl-based intermetallic compound sintered body of the example. FIG. 15 is a graph showing the relationship between the Ni and Fe contents and the sintered density.

As shown in FIG. 11, the TiAl-based intermetallic compound sintered body Fx according to Comparative Example 3 has a Ni content of 0.34% by weight and a Fe content of 1.79% by weight. That is, the TiAl-based intermetallic compound sintered body Fx according to Comparative Example 3 has a total content of Ni and Fe of 2.13% by weight. In addition, the TiAl-based intermetallic compound sintered body F according to Examples 3 and 4 has a Ni content of 0.17% by weight and a Fe content of 0.92% by weight. That is, in the TiAl-based intermetallic compound sintered body F according to Examples 3 and 4, the total content of Ni and Fe is 1.09% by weight. Further, the TiAl-based intermetallic compound sintered body Fx according to Comparative Example 3 is the same method as in the third embodiment, and in Example 4, the method of the third embodiment, that is, the TiAl-based powder B ₁ a and applying the method of mixing the additive metal powder B _{3 a.} On the other hand, in Example 3, the method of the first embodiment, that is, by applying the manufacturing method using the TiAl-based solid solution powder B ₁ containing the additive metal and TiAl-based intermetallic compound.

  As shown in FIG. 11, the TiAl-based intermetallic compound sintered body Fx according to Comparative Example 3 has a sintered density of 97%, as shown in FIG. Colonies of On the other hand, the TiAl-based intermetallic compound sintered body F according to Example 3 has a sintered density of 99%, as shown in FIG. 11, a small number of voids V, and a γ phase, as shown in FIG. No colony has been generated. The TiAl-based intermetallic compound sintered body F according to Example 4 has a sintered density of 97% as shown in FIG. 11, a small number of voids V and a γ-phase colony as shown in FIG. Neither has occurred.

The horizontal axis in FIG. 15 is the total content of Ni and Fe, and the vertical axis is the sintered density. FIG. 15 is a plot of the results of Comparative Examples 1 and 3 and Examples 3 and 4. As shown in FIG. 15, the TiAl-based intermetallic compound sintered body F containing Ni and Fe as additive metals, when the total amount of Ni and Fe is 0.1 wt% or more and 2 wt% or less of the whole, The sintered density is high, and the generation of γ-phase colonies can be suppressed. Further, referring to Example 3 and Example 4, even if the method of the third embodiment, that is, the production method of mixing the TiAl-based powder B ₁ a and the additive metal powder B ₃ a, It can be seen that the sintering density can be increased even by the method, that is, the production method using the TiAl-based solid solution powder B ₁ containing the TiAl-based intermetallic compound and the additive metal.

  FIG. 16 is a table showing the sintered density of the example and the comparative example. FIG. 17 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the comparative example. FIG. 18 is a diagram of the metal structure of the TiAl-based intermetallic compound sintered body of the example. As shown in FIG. 16, the TiAl-based intermetallic compound sintered body Fx according to Comparative Example 4 has an Fe content of 1.08% by weight and an Ni content of less than 0.01% by weight. In the TiAl-based intermetallic compound sintered body F according to Example 5, the Fe content is 2.13 wt% and the Ni content is less than 0.01 wt%. In Comparative Example 4 and Example 5, the sintering temperature is 1420 ° C. For the rest, Comparative Example 4 and Comparative Example 1 have the same conditions, and Example 5 has the same conditions as Example 1.

  The TiAl-based intermetallic compound sintered body Fx according to Comparative Example 4 has a sintered density of 93% as shown in FIG. 16 and a large number of voids V as shown in FIG. On the other hand, the TiAl-based intermetallic compound sintered body F according to Example 5 has a sintered density of 98%, as shown in FIG. 16, has a small number of pores V, and has a γ phase as shown in FIG. No colony has been generated.

  As described above, the TiAl-based intermetallic compound sintered body F can increase the sintered density when the content of Fe is 2% by weight or more when only Fe is used as the additive metal.

  As mentioned above, although embodiment of this invention was described, embodiment is not limited by the content of this embodiment. In addition, the above-described constituent elements include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the above-described components can be appropriately combined. Furthermore, various omissions, substitutions, or changes of the components can be made without departing from the spirit of the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 Sintered body manufacturing system 10 Powder manufacturing apparatus 20 Metal powder injection molding apparatus 30 Degreasing apparatus 40 Sintering apparatus A ₁ TiAl system ingot A ₂ TiAl system melt B ₁ TiAl system solid solution powder B ₁ a TiAl system powder B ₂ TiAl Powder body B ₃ a additive metal powder C mixture D compact E degreased body F TiAl intermetallic compound sintered body F1 TiAl system sintered powder F2 TiAl phase F3 additive metal phase

Claims (10)

A TiAl-based intermetallic compound in which Ti and Al are combined and a TiAl-based powder body containing an additive metal are sintered to produce a TiAl-based intermetallic compound sintered body,
The method for producing a TiAl-based intermetallic compound sintered body, wherein the additive metal is Ni or Ni and Fe. A mixing step of mixing the TiAl powder body and a binder to obtain a mixture;
An injection molding step of molding the mixture into a molded body by a metal powder injection molding machine;
A degreasing step of degreasing the molded body to produce a degreased body;
A method for producing a TiAl-based intermetallic compound sintered body according to claim 1, further comprising a sintering step of sintering the degreased body to produce the TiAl-based intermetallic compound sintered body.   The method for producing a TiAl-based intermetallic compound sintered body according to claim 1 or 2, wherein the TiAl-based powder body has a Ni content of 0.01 wt% or more and 1 wt% or less.   The TiAl-based intermetallic compound sintering according to any one of claims 1 to 3, wherein the TiAl-based powder body has a total amount of Ni and Fe of 0.01 wt% or more and 2 wt% or less. Body manufacturing method.   The TiAl-based powder body according to any one of claims 1 to 4, wherein the TiAl-based powder body is a mixture of a plurality of TiAl-based solid solution powders containing the TiAl-based intermetallic compound and the additive metal. Of producing a sintered intermetallic compound.   5. The TiAl powder body according to any one of claims 1 to 4, wherein the TiAl powder is a mixture of a TiAl powder that is a powder of the TiAl intermetallic compound and an additive metal powder containing the additive metal. 2. A method for producing a TiAl-based intermetallic compound sintered body according to item 1. A TiAl-based intermetallic compound in which Ti and Al are bonded, and an additive metal that is Ni;
A TiAl-based intermetallic compound sintered body in which the Ni content is 0.01 wt% or more and 1 wt% or less of the whole. A TiAl-based intermetallic compound in which Ti and Al are bonded, and an additive metal that is Ni and Fe,
A TiAl-based intermetallic compound sintered body in which the total content of Ni and Fe is 0.01% by weight or more and 2% by weight or less of the whole.   The TiAl-based intermetallic compound contains 20 to 80 wt% Ti, 20 to 80 wt% Al, and 0 to 30 wt% mixed metal, and the mixed metal includes Nb, Cr, and Mn The TiAl-based intermetallic compound sintered body according to claim 7 or 8, which contains at least one of them.   A plurality of TiAl-based sintered powders containing the TiAl-based intermetallic compound and the additive metal are combined, and the additive metal phase that is the metal phase of the additive metal is between adjacent TiAl-based sintered powders. The TiAl-based intermetallic compound sintered body according to any one of claims 7 to 9, wherein the sintered body is a TiAl-based intermetallic compound.