JPH03111523A - Production of metal-based composite material - Google Patents

Abstract

PURPOSE:To produce the metal-based composite material dispersed with intermetallic compds. by impregnating the molten metal of Al, Mg, etc., into a porous molding contg. an inorg. reinforcing material, fine pieces of metals, and fine pieces of a metal fluoride, and then subjecting the molding to enforce cooling. CONSTITUTION:The porous molding 16 contg. the inorg. reinforcing material 12, such as SiC whiskers, the metal powder 10 of stainless steels, etc., which form the intermetallic compd. by reacting with Al or Mg and the powder 14 of the metal fluoride, such as K2ZrF6, is formed. This molding 16 is immersed into the molten metal 18 to penetrate the molten matrix metal 18 of Al, Mg, alloys thereof, etc., in the molding. The impregnated molding 16 is then taken out and is imposed on an iron plate, by which the molding is compulsorily cooled to regulate the intermetallic reaction. The composite material 22 which contains the reinforcing material 12, such as SiC, in the matrix metal of Al, etc., finely dispersed with a proper ratio of the intermetallic compds. 24 of Fe3Al24, etc., and has good performance is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a metal matrix composite material, and more specifically, it uses inorganic fibers such as ceramic fibers as a reinforcing material, and contains fine intermetallic compounds in the matrix metal. The present invention relates to a method for producing a dispersed metal matrix composite material.

Conventional Technology As one method for manufacturing a metal matrix composite material containing an intermetallic compound in the matrix metal, the applicant of the present application has proposed an inorganic reinforcing material and , a metal that reacts with Al to form an intermetallic compound;
・Form a porous molded body containing fine pieces of metal fluoride, bring at least a portion of the molded body into contact with a molten metal of Al or an Al alloy, and pressurize the molten metal substantially without pressurizing the molded body. We proposed a manufacturing method for intermetallic compound composite materials that can be infiltrated into

Generally, the metal that reacts with AI to form an intermetallic compound is A.
Since the I or Al alloy has excellent wettability to the molten metal, the molten metal permeates into the molded body through the fine pieces of metal. The metal fluoride also removes the oxide film on the surface of the molten metal and fine metal pieces, thereby improving the wetting of the molten metal to the reinforcing material. In addition, the molten metal and the metal react with each other to form intermetallic compounds and generate heat, which heats the molten metal and the reinforcing material, which improves the permeability of the molten metal into the compact and the wettability of the reinforcing material. As a result, the molten metal penetrates into the molded body well, and intermetallic compounds are successively formed between the individual reinforcing materials.

Therefore, according to this method, there is no need to pressurize the molten metal or preheat the reinforcing material to a high temperature, so composite materials containing intermetallic compounds in the matrix can be produced more efficiently and inexpensively than with hot pressing methods etc. can do.

Furthermore, according to the method proposed in the future, the molten metal penetrates into the molded body well as described above, so that the molded body containing the reinforcing material, metal, and fine pieces of metal fluoride can be shaped into a predetermined shape. If a part of the molded body is brought into contact with molten metal, the molten metal will quickly penetrate into the entire molded body in just the right amount and an intermetallic compound will be formed. A dimensional composite material is formed. Therefore, composite materials of substantially predetermined shapes and dimensions can be produced efficiently and inexpensively with very high yields.

Problems to be Solved by the Invention However, in the composite material method proposed above, the molten metal and metal react with each other and generate heat, which accelerates their combination reaction. Depending on the type and amount of metal, the compounding reaction may proceed significantly, resulting in an excessive amount of intermetallic compounds in the matrix metal, which may cause the matrix metal to become brittle or cause thermal deterioration of the reinforcing material. There is a problem in that properties such as strength and abrasion resistance of composite materials cannot be sufficiently improved.

In view of the above-mentioned problems in the above-mentioned methods for producing composite materials, the present invention aims to efficiently produce composite materials having good performance in which an appropriate amount of intermetallic compounds are finely dispersed in the matrix metal. The purpose is to provide a method that can be manufactured easily and inexpensively.

Means for Solving the Problems According to the present invention, the above object is to provide an inorganic reinforcing material, fine pieces of metal that react with Al or Mg to form an intermetallic compound, and fine pieces of metal fluoride. forming a porous molded body containing the above, infiltrating a molten metal of a matrix metal selected from the group consisting of At SMg, Al alloy, and Mg alloy into the molded body, and then forcibly cooling the molded body. This is achieved by a method of manufacturing a base composite material.

According to one detailed feature of the invention, the molded body comprises a reinforcing material, fine pieces of a metal (hereinafter referred to as specific metal) that reacts with Al or Mg to form an intermetallic compound, and fine pieces of a metal fluoride. or by adhering fine pieces of metal fluoride to the surface of the reinforcement and the particular metal fine pieces, thus forming a mixture of the treated reinforcement and the particular metal fine pieces. It is formed by

According to one embodiment of the present invention, a reinforcing material made of a specific metal is used as the reinforcing material, thereby eliminating the need to mix separate fine pieces of the specific metal into the molded body.

According to another embodiment of the present invention, the inorganic reinforcing material, the specific metal fine pieces, the metal fluoride fine pieces, and the matrix metal have excellent wettability with the molten metal. A molded body consisting of fine pieces of metal that do not substantially undergo chemical reaction is formed.

Further, in the method of the present invention, the metal fluoride may be a fluoride of any metal element, but for example, 2 ZrF6
K2 TiF6, KAlF4 K3AlF6
, K2AlF3-H20SCsAIF4CsAIF
5 Ti combined with electrically positive elements such as alkali metals, alkaline earth metals, and rare earth metals, such as ψH and O,
Transition metals such as Zr, Hf, , VSNb, Ta or Al
It is preferable that it is a fluoride containing. According to another detailed feature of the invention, therefore, the metal fluoride is a fluoride containing a transition metal or Al in combination with an electrically positive metal element.

Further, in the method of the present invention, the metal constituting the metal fine pieces may be any metal as long as it reacts with Al or Mg to form an intermetallic compound, but in particular, the matrix metal may be At or an Al alloy. If Ni5Fe, Co
, Cr, Mn, Cu.

Ag, Si, Mg, Zr5ZnSSn, Pb, Ti%
Nb or an alloy containing any of these as the main component is preferable, and when the matrix metal is Mg or an Mg alloy, Ni, Fe, CO% Cr, Mn, Cu, A
g5S i, Z r, %Zn, Sn, Pb%Ti, Nb
, or an alloy containing either of these as a main component is preferable. According to another detailed feature of the invention, therefore, the metal constituting the metal particles is N15FeSCo, C
rSMn5Cu, Ag5S 15Mg5Z rSZn.

Selected from the group consisting of Sn, Pb, Ti5Nb, and alloys containing any of these as main components, and when the matrix metal is Mg or Mg alloy, Ni, Fe, Co
, Cr, Mn, Cu%Ag,%S1, Zr, Zn5S
The material is selected from the group consisting of nSPb, Tib Nb, or an alloy containing any of these as a main component.

In the method of the present invention, it is not necessary to preheat the compact, but when preheating the compact to improve the wettability of the reinforcing material and fine metal pieces to the molten metal, the temperature The temperature is preferably lower than conventionally employed temperatures. Further, the fine particles of metal and metal fluoride in the present invention may be in any form such as powder, whiskers, or short fibers.

In addition, in the method of the present invention, the reinforcing material may have any form and material, for example, silicon carbide fibers, ceramic fibers such as alumina fibers, iron fibers, metal fibers such as tungsten fibers, carbon fibers, etc. The particles may be inorganic fibers other than ceramics and metals such as ceramics and metals, whiskers such as silicon carbide whiskers, silicon carbide particles, and titanium carbide particles.

Effect of the Invention According to the method of the present invention, a porous molded body containing an inorganic reinforcing material, fine pieces of a specific metal, and fine pieces of metal fluoride is formed, and the A alloy is contained in the molded body. The molded body is then forcedly cooled.

In general, certain metals, such as Al alloys, have excellent wettability with molten metal, so the molten metal penetrates into the molded body through the specific metal. Metal fluoride also removes oxide films on the surface of the molten metal and certain metals to improve wetting of the molten metal to the reinforcing material. In addition, the molten metal and specific metals react with each other to form intermetallic compounds and generate heat, which heats the molten metal and the reinforcing material, which improves the permeability of the molten metal into the compact and the wettability of the reinforcing material. As a result, the molten metal permeates well into the molded body, and the intermetallic compound is successively formed in a finely dispersed state in the matrix metal. In addition, during this process, the molded body penetrated by the molten matrix metal is forcibly cooled, and as a result, the chemical reaction between the molten metal and a specific metal is forcibly terminated. This avoids embrittlement of the matrix metal due to an excessive amount of compounds and thermal deterioration of the reinforcing material due to an excessive amount of reaction heat, and further refines the structure of the matrix metal. is achieved.

Thus, according to the method of the present invention, a suitable amount of intermetallic compound is finely dispersed in the matrix metal, thus forming a composite material with good performance.

Furthermore, according to the method of the present invention, the reaction between the molten metal and the specific metal is prevented by forced cooling of the molded body into which the molten metal of the matrix metal has permeated, regardless of the type of the matrix metal or the specific metal. Because it is forced to terminate,
It is no longer necessary to strictly adjust the volume fraction of the specific metal fine particles in the compact depending on the type of the matrix metal and the specific metal in order to form an appropriate amount of intermetallic compound in the matrix metal.

In this specification, "forced cooling" means cooling the molded article at a higher cooling rate than air cooling.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

Example 1 Stainless steel powder with an average particle size of 40 μm (JIS standard 5U
S430), average fiber diameter 1.0 μm, average fiber length 300
SiC whiskers of μI and 2Z of average particle size of 40μta
r FB powder at a ratio of 1.2:1. :0.04, and the mixture was compression-molded in a mold into a cylindrical shape with a diameter of 30IIff11 and a height of 5mm, as shown in Fig. 1, stainless steel powder 10 and SiC A porous molded body 16 made of ZrF6 powder 14 was formed on the whisker 12.

Next, after preheating this molded body to about 100°C for about 10 minutes, the molded body 16 was heated to about 750°C as shown in FIG.
It is immersed in a molten metal 18 of pure AI for 10 seconds and taken out from the molten metal.
The molded body 16' penetrated with the molten metal is 30X30X, 1.2
By placing it on an iron plate (JIS standard 5PCC) 20 having dimensions of
1 of the molten metal is forcedly cooled and solidified, thereby forming SiC whiskers 1 with a volume fraction of 20%, as shown in FIG.
In step 2, a cylindrical composite material 22 made of compositely reinforced pure AI was formed.

Next, the thus formed composite material was cut along a plane passing through its axis, and the cross section was observed using an optical microscope. It was found that an appropriate amount of the intermetallic compound Fe5Al24 produced by the above was finely dispersed, and the properties of the SiC whiskers were also good.

The volume fraction of SiC whiskers was approximately 20%.

For the purpose of comparison, the molded body was immersed in a pure Al molten metal, taken out from the molten metal, and then left in the air, so that the pure AI molten metal that had penetrated into the molded body was air-cooled. A composite material was produced in the same manner and under the same conditions as in Example 1, and the cross section of the composite material was observed with an optical microscope. As a result, in the composite material of this comparative example, the reaction between the stainless steel powder and pure AI progressed significantly,
It was found that a very large amount of intermetallic compound Fe3Al was generated in pure Al as the matrix metal, and that this caused the matrix metal to become extremely brittle.

Example 2 Ni powder with an average particle size of 2 μm is used instead of stainless steel powder to form Ni powder and SiC whiskers! ! Zr
The mixing ratio with F6 powder is 1. The temperature was set to 1:8 A composite material was manufactured in the same manner and under the same conditions as in Example 1 above, except that the thickness of the iron plate for forced cooling of the molten aluminum alloy was set to 1 mm, and the cross section of the composite material was was observed using an optical microscope.

As a result, this composite material also contains an appropriate amount of intermetallic compound Ni3 in the aluminum alloy as the matrix metal.
It was found that Al was finely dispersed and the properties of the SIC whiskers were good. The volume fraction of SiC whiskers was about 10%.

For the purpose of comparison, a composite material was manufactured using the same procedure and conditions, except that the molded body impregnated with the molten aluminum alloy was cooled in the air. The reaction proceeded rapidly, generating rapid heat generation, and as a result, the molded product was scattered into the air.

Example 3 Ni powder with an average particle size of 15 μm and T with an average particle size of 4 μm
i powder, average fiber diameter] -10 μm, average fiber length 300
µl of SiC whiskers and KA I with an average particle size of 20 µl.
A molded body consisting of F4 powder was formed, the mixing ratio of these was set to 1.1:0.7:l:0.4, and the preheating temperature and time of the molded body were set to approximately 300°C and 20 minutes, respectively. The method described above was carried out as follows, except that an aluminum alloy (JIS standard AC8A) at about 750°C was used as the molten matrix metal, and the molded body impregnated with the molten aluminum alloy was forcedly cooled by placing it in water. A composite material was produced in the same manner and under the same conditions as in Example 1, and the cross section of the composite material was observed with an optical microscope.

As a result, this composite material also contains an appropriate amount of intermetallic compound Ni3 in the aluminum alloy as the matrix metal.
It was found that Al was finely dispersed and the properties of the SiC whiskers were also good. The volume fraction of SiC whiskers was approximately 10%.

For comparison purposes, a composite material was manufactured using the same procedure and conditions, except that the molded body impregnated with molten aluminum alloy was cooled in air. It was observed that the reaction progressed significantly and a very large amount of intermetallic compound N i 3 A 1 was generated in the matrix metal, which caused the matrix metal to become extremely brittle.

Example 4 Stainless steel M fibers (JIS standard 5US430) with an average fiber diameter of 20 μm and an average fiber length of 1 mm were used instead of stainless steel powder and SiC whiskers, and the mixing ratio of the stainless steel fibers and the 2 Zr Fa powder was 1. :0.1, the preheating temperature of the molded body was set to 200°C, and an aluminum alloy (JIS standard AC8A) at about 750°C was used as the molten matrix metal, and the molded body and the aluminum alloy infiltrated into it were A composite material was produced in the same manner and under the same conditions as in Example 1 above, except that the thickness of the iron plate for forced cooling of the molten metal was set to 1.6 mm. The cross section was observed using an optical microscope.

As a result, in this composite material, two suitable intermetallic compounds F e are present in the aluminum alloy as the matrix metal.
3 A1 was finely dispersed, and although the fiber diameter and fiber length were slightly reduced, it was observed that the stainless steel fibers maintained their properties as fibers. The volume percentage of stainless steel fibers was approximately 20%.

For comparison purposes, a composite material was manufactured using the same procedure and conditions, except that the molded body impregnated with molten aluminum alloy was cooled in the air. The reaction with AI progressed significantly, and a very large amount of intermetallic compound Fe3Al was generated in the matrix metal, which caused the matrix metal to become extremely brittle, and the original stainless steel M fiber was significantly altered. It was observed that the fibers had already lost their form as fibers.

Example 5 Ni powder with an average particle size of 2 μm was used instead of stainless steel powder, potassium titanate whiskers with an average fiber diameter of 3 μm 1 average fiber length of 30 μl were used as reinforcement, and N
2 Zr F5 to l powder and potassium titanate whiskers
The mixing ratio with the powder was set to 0.7:1:40X10-3, the preheating temperature of the compact was set to about 300°C, and a pure Mg molten metal at about 740°C was used as the matrix metal molten metal. A composite material was produced in the same manner and under the same conditions as in Example 1 above, except for the above, and the cross section of the composite material was observed with an optical microscope.

As a result, it was found that an appropriate amount of the intermetallic compound MgpNi was finely dispersed in pure Mg as the matrix metal, and the properties of the potassium titanate whiskers were also good. The volume fraction of potassium titanate whiskers is approximately 20
%Met.

For comparison purposes, a composite material was manufactured using the same procedure and conditions, except that the molded body impregnated with pure Mg molten metal was cooled in air. It was observed that the reaction progressed significantly and a very large amount of intermetallic compound MgpNi was generated in the matrix metal, which caused the matrix metal to become extremely brittle.

Furthermore, instead of pure Mg molten metal, Mg alloy (JIS
It was confirmed that even when standard MC2) was used, a good composite material could be produced in the same way as in this example.

Example 6 Ni with an average particle size of 1511 m instead of stainless steel powder
SiC powder with an average particle size of 5 μm is used as reinforcement.
2ZrFs is used in Ni powder and SiC powder.
The mixing ratio with the powder was set to 0.3:], :2×10-3, the preheating temperature of the compact was set to 300°C, and the aluminum alloy (at about 750°C) was used as the molten matrix metal.
Same as in Example 1 above, except that JIS standard AC8A) was used and the thickness of the iron plate for forced cooling of the molded body and the molten aluminum alloy permeated therein was set to 6 m + m. A composite material was manufactured using the same procedure and conditions, and the cross section of the composite material was observed using an optical microscope.

As a result, this composite material also contains an appropriate amount of intermetallic compound Ni3 in the aluminum alloy as the matrix metal.
It was found that Al was finely dispersed and the properties of the SiC particles were also good.

The volume fraction of SiC particles was about 20%.

For comparison purposes, a composite material was manufactured using the same procedure and conditions, except that the molded body impregnated with molten aluminum alloy was cooled in air. It was observed that the reaction progressed significantly and a very large amount of intermetallic compound Ni3Al was generated in the matrix metal, which caused the matrix metal to become extremely brittle.

Although the present invention has been described above in detail with reference to several embodiments, the present invention is not limited to these embodiments, and various embodiments of the pond are possible within the scope of the present invention. It will be clear to those skilled in the art that

Effects of the Invention According to the method of the present invention, in the process in which the molten metal of the matrix metal permeates into the compact and the intermetallic compounds are sequentially formed in a finely dispersed state in the matrix metal, the matrix metal is The amount of intermetallic compounds in the matrix metal becomes too large due to forced cooling of the molded body penetrated by molten metal, which forcibly terminates the chemical reaction between the molten metal and a specific metal. The embrittlement of the matrix metal caused by this and the thermal deterioration of the reinforcing material caused by the excessive amount of reaction heat generated are avoided.
Furthermore, the microstructure of the matrix metal can be refined.

For example, FIGS. 5 and 6 are graphs showing the relationship between the cooling rate of a molded body permeated with molten matrix metal and the bending strength and wear amount of the composite material, respectively. From these graphs, it can be seen that the strength and wear resistance of the composite material can be improved by forcibly cooling the compact into which the molten matrix metal has permeated.

Thus, according to the method of the present invention, by appropriately setting the time and cooling rate after the molten matrix metal is infiltrated into the molded body until the molded body is forcibly cooled, an appropriate amount of matrix metal can be contained in the matrix metal. It is possible to produce a composite material in which intermetallic compounds are finely dispersed and have good performance.

Furthermore, according to the method of the present invention, the reaction between the molten metal and the specific metal is prevented by forced cooling of the molded body into which the molten matrix metal has permeated, regardless of the type and amount of the matrix metal or the specific metal. Because it is forced to terminate,
It is not necessary to strictly adjust the volume fraction of the specific metal fine pieces in the compact depending on the type of matrix metal and specific metal in order to form an appropriate amount of intermetallic compound in the matrix metal, Therefore, as described above, a composite material in which an appropriate amount of the intermetallic compound is finely dispersed in the matrix metal and has good performance can be produced efficiently and at low cost.

[Brief explanation of drawings]

Figures 1 to 4 are process diagrams showing a series of manufacturing steps according to one embodiment of the method for manufacturing a metal matrix composite material according to the present invention, and Figures 5 and 6 are moldings in which the molten metal of the matrix metal permeates, respectively. 3 is a graph showing the relationship between the cooling rate of a body and the bending strength and wear amount of a composite material. DESCRIPTION OF SYMBOLS 10... Stainless steel powder, 12... SiC whisker 14-Kp Z r F6 powder, 16-... Molded body, 18... Molten metal of pure AI, 20... Iron plate, 22...
・Composite materials. 24... Intermetallic compound patent applicant: Toyota Motor Corporation representative
Masaki Akashi, Patent Attorney 1 Figure 24...Goshitsuru Threshold 1c Right] Figure Cooling Rate Figure Cooling Rate

Claims (1)

[Claims] A porous molded body containing an inorganic reinforcing material, fine pieces of metal that react with Al or Mg to form an intermetallic compound, and fine pieces of metal fluoride is formed, and A
1. A method for producing a metal matrix composite material, which comprises infiltrating a molten matrix metal selected from the group consisting of Mg, Mg, Al alloy, and Mg alloy, and then forcibly cooling the molded body.