JPH0645833B2 - Method for manufacturing aluminum alloy-based composite material - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite material, and more particularly, to an aluminum alloy-based composite material containing aluminum alloy as a matrix and short fibers, whiskers or particles as a reinforcing material. It relates to the manufacturing method.

Conventional technology In order to improve the wear resistance of aluminum alloy while taking advantage of its light weight, it has been studied intensively to strengthen aluminum alloy with various reinforcing materials such as fibers and particles. There is. For example, JP-A-58-58
In each publication of 93841 and 59-70736,
(1) Aluminum alloy compound-reinforced with ceramic fibers, (2) Aluminum alloy compound-reinforced with ceramic whiskers, (3) Aluminum alloy compound-reinforced with nickel in a three-dimensional network structure, (4) Cast iron Aluminum alloys that are composite reinforced with fibers are described.

The composite material is superior in wear resistance to the aluminum alloy alone, but especially in the composite materials of (1) and (2) described above, the resistance of the composite material itself is high. Although the wear resistance is extremely excellent, there is a problem in that the amount of wear of the mating material that frictionally slides with the composite material increases because the reinforcing material is a hard ceramic reinforcement material. (3) and (4) In the composite material (1), since the hardness of the reinforcing material is low, the aggressiveness to the mating material is low, but there is a problem that the wear resistance of the composite material itself is not sufficient. Therefore, depending on these conventional aluminum alloy-based composite materials, it is difficult to simultaneously improve the wear resistance of the composite material itself and reduce the wear amount of the mating material.

Further, various experimental studies have been conducted on the application of the conventional aluminum alloy-based composite material as described above. As a result, for example, in a piston of an internal combustion engine, such a composite material is an aluminum alloy at an extremely high temperature of 200 ° C. or higher. It has been found that when it is applied to a sliding member that is used as a material, abrupt wear, that is, cohesive wear due to transfer of the matrix aluminum alloy to the sliding counterpart material is likely to occur. In addition, this adhesive wear normally prevents the matrix from coming into direct contact with the sliding mating material by the reinforcing material, whereas it softens when the aluminum alloy is heated to a high temperature, resulting in It was found that the reinforcing material on the surface of the material was not properly held by the matrix and the softened aluminum alloy was brought into direct contact with the sliding mating material.

As a means for avoiding the occurrence of such adhesive wear, it is conceivable to improve the heat resistance of the composite material, and as a means for improving the heat resistance of the composite material, increase the amount of reinforcing material such as fibers and particles. This has been generally done from the past. However, as a result of various experimental studies on this point as well, when the amount of the reinforcing material is increased, the amount of wear of the mating material tends to increase, and even when the amount of the reinforcing material is increased, only the matrix is formed on the surface of the composite material. It was found that it was not possible to completely avoid the occurrence of adhesive wear, since the portion marked with remained.

The inventors of the present application have conducted various experimental studies in view of the above-mentioned problems in conventional aluminum alloy-based composite materials, and as a result, in the aluminum alloy as a matrix, A
According to the aluminum alloy-based composite material in which the intermetallic compound of 1 and a specific metal element is finely dispersed and the volume ratio of the intermetallic compound is set to a predetermined value, the amount of wear of the mating material is increased. It has been found that the adhesion resistance of the composite material can be improved significantly without any.

That is, in the conventional research and development of aluminum alloy-based composite materials, the idea that the matrix is a carrier that bears stress transfer between reinforcements is dominant, and the matrix must have relatively high toughness. Has been considered. Therefore, efforts have been made to suppress precipitation of intermetallic compounds, which causes embrittlement of the matrix, as much as possible. However, as a result of various experimental studies, in order to improve the adhesion resistance of an aluminum alloy-based composite material at a high temperature of 200 ° C or higher, an intermetallic compound, which has been considered to be a cause of embrittlement, is conventionally used as a matrix. It is extremely effective to disperse it by finely precipitating it in the inside, and wear resistance and adhesion resistance at high temperature can be set by appropriately setting the type, amount, and formation form of intermetallic compounds. It has been found that a high-performance composite material that is excellent in performance and does not increase the amount of wear of the mating material can be obtained.

Incidentally, the above-mentioned JP-A-59-218341 and JP-A-61
As described in JP-A-132260, a composite material in which an intermetallic compound is formed in a matrix of an aluminum alloy is already known. However, in these composite materials, the part where the intermetallic compound is formed is only the part around the reticulated structure and the part around the cast iron fiber, and the cell part of the reticulated structure (the void part of the reticulated structure is ) And the matrix part between the cast iron fibers, the cell part of the reticulated structure and the matrix between the cast iron fibers consist essentially of aluminum alloy with low heat resistance, so that no intermetallic compound is formed. Although it is possible to improve the wear resistance as compared with the composite material, the occurrence of adhesion at a high temperature of 200 ° C. or higher cannot be avoided.

The present invention is based on the knowledge obtained as a result of experimental research conducted by the inventors of the present application, and is excellent in wear resistance and adhesion resistance at high temperatures, and does not increase the wear amount of the mating material. Moreover, it is an object of the present invention to provide an aluminum alloy-based composite material having a strength equal to or higher than that of a conventional composite material.

Means for Solving the Problems According to the present invention, the above-mentioned object is a method for producing an aluminum alloy-based composite material using aluminum alloy as a matrix and ceramic short fibers, ceramic whiskers or ceramic particles as a reinforcing material, and Reinforcement and F
e, Ni, Co, Cr, Cu, Mn, Mo, V, W, T
A porous compact is formed from a substantially uniform mixture of fine particles of at least one metal element selected from the group consisting of a, Nb, Ti, and Zr, and a molten aluminum alloy is formed in the compact. And then solidify the molten metal, thereby substantially uniformly and finely dispersing the intermetallic compound of A1 and at least one of the metal elements in the matrix between the reinforcing materials, This is achieved by a method for producing an aluminum alloy-based composite material, characterized in that the volume ratio of the intermetallic compound in the matrix is 5 to 70%.

EFFECTS AND EFFECTS OF THE INVENTION According to the present invention, an intermetallic compound of A1 and another predetermined metal element is substantially uniformly and finely dispersed in an aluminum alloy as a matrix, and the intermetallic compound forms a reinforcing material. The matrix between them is strengthened, i.e., solidified, which keeps the reinforcement in place even at high temperatures and avoids direct contact of the matrix with the mating material, compared to conventional composite materials. Therefore, it is possible to manufacture a composite material having excellent wear resistance and adhesion resistance at high temperature, and since the volume ratio of the reinforcing material is not increased, it is necessary to increase the wear amount of the mating material. It is possible to produce a composite material without. The intermetallic compound itself is a hard and brittle substance, but the volume ratio of the intermetallic compound in the matrix is set to 5 to 70%, and the intermetallic compound is substantially uniformly and finely dispersed in the matrix. So
A composite material having strength equal to or higher than that of a conventional composite material containing no intermetallic compound can be easily manufactured.

Further, for example, only an intermetallic compound forming material, that is, a material consisting of a metal element that reacts with A1 in the matrix to form an intermetallic compound is mixed with the matrix, and the surface portion of the intermetallic compound forming material reacts with A1 in the matrix. A method is also conceivable in which the intermetallic compound is formed by the reaction and the central portion of the intermetallic compound-forming material is left in an unreacted state as a kind of reinforcement.

However, in the case of such a method, the intermetallic compound is formed only around the substantially unreacted intermetallic compound-forming material and in an integrated state therewith, and the intermetallic compound is formed in the matrix between the reinforcing materials. Cannot be dispersed uniformly and finely. Further, the unreacted intermetallic compound-forming material cannot perform a sufficient function as a reinforcing material, and the reinforcing material is limited to a specific metal that reacts with A1 to form an intermetallic compound. The forming material must be relatively large because the center of the forming material needs to remain in an unreacted state, so that the surface portion of the intermetallic compound forming material is sufficiently reacted with A1 in the matrix. First, the mixture of the intermetallic compound forming material and the matrix must be heat treated. Furthermore, it is very difficult to set the volume ratio and size of the intermetallic compound independently of the volume ratio and size of the reinforcing material according to the properties required for the composite material.

On the other hand, in the method of the present invention, the intermetallic compound forming material is provided as fine particles separate from the reinforcing material, and the reinforcing material itself does not substantially participate in the formation of the intermetallic compound. Therefore, the matrix is not only uniformly strengthened by the intermetallic compound dispersed therein substantially uniformly and finely, and the reinforcement is not only well retained by the matrix well consolidated by the intermetallic compound, but also the reinforcement. Is a reinforcing material made of ceramics that is superior in hardness and high temperature stability to metals, and fully exhibits its original function without causing deterioration of the reaction with the molten metal of the matrix. It is possible to improve properties such as abrasion resistance and adhesion resistance at high temperature of the composite material as compared with the case of mixing with the matrix. Further, the intermetallic compound-forming material is a fine piece that does not need to remain unreacted at the center, and since it easily reacts with A1 in the matrix at the same time as it is made into a composite by allowing the molten metal of the matrix to permeate into the molded body. , It is not necessary to heat them after the molten matrix has penetrated into the compact. Furthermore, the volume ratio and size of the intermetallic compound can be easily and surely set to a value within the preferable range independently of the volume ratio and size of the reinforcing material, and particularly, the volume ratio of the intermetallic compound in the matrix can be set. Can be easily and surely made 5 to 70%.

Further, for example, a composite material in which the intermetallic compound is dispersed in the matrix is also produced by mixing a matrix powder containing a metal element that forms a intermetallic compound by undergoing a chemical reaction with each other and a reinforcing material and sintering the mixture. be able to. However, in the case of such a method, a compact having a higher density than that of the porous compact according to the present invention must be formed by compressing a mixture of the reinforcement and the matrix powder. Deterioration is likely to occur, the composition of the matrix is limited to those containing a specific metal element, and it is difficult to control the volume ratio of the intermetallic compound produced within a predetermined range. The produced intermetallic compound is very small, and small holes due to sintering are likely to occur, so that the properties such as thermal shock properties of the composite material part cannot be sufficiently improved. Further, when the size of the matrix powder is larger than the size of the reinforcing material, the reinforcing material is unevenly distributed in the area around the original matrix powder in a microscopic view, and the area corresponding to the inside of the original matrix powder. It tends to have a non-uniform structure with no reinforcing material.

On the other hand, in the method of the present invention, the molten metal of the aluminum alloy is infiltrated into the porous compact formed of a substantially uniform mixture of the reinforcing material and the fine particles of the specific metal element, so that the metal Since the intermetallic compound is formed, the reinforcing material and the intermetallic compound can be dispersed more uniformly and finely as compared with the case of the above-mentioned sintering method, and the compact is lower than that in the case of sintering. Since it is a porous molded body having a high density and it is not necessary to compress the mixture to a high pressure, deterioration such as breakage of the reinforcing material can be reduced, and thereby a high-performance composite material can be manufactured.

Further, according to the method of the present invention, the composition of the matrix is not limited to the one containing a specific metal element, and the volume ratio and the size of the fine pieces in the molded body can be appropriately set to obtain an intermetallic composition. The volume ratio of the compound can be easily and reliably controlled to the preferable range of 5 to 70%, and the size thereof can be easily controlled, and further, the composite material having substantially no pores. Therefore, a composite material having excellent wear resistance and adhesion resistance can be easily manufactured.

According to the results of the experimental research conducted by the inventors of the present application, when the volume ratio of the reinforcing material is too low, the wear resistance and the adhesion resistance of the composite material cannot be sufficiently improved, and conversely If the volume ratio of the reinforcing material is too high, the amount of wear of the mating material increases.
Therefore, according to one particular feature of the method of the invention, the volume fraction of the reinforcement is set between 3 and 30%.

According to the results of the experimental research conducted by the inventors of the present application,
The volume ratio of the intermetallic compound in the matrix may be 5 to 70%, but in order to further improve the adhesion resistance at high temperature, the volume ratio of the intermetallic compound in the matrix is 10 to 40%. % Is preferable. Therefore, according to another particular feature of the method of the present invention, the volume fraction of intermetallic compound in the matrix is set to 10-40%.

According to the results of the experimental research conducted by the inventors of the present application,
The intermetallic compounds are preferably dispersed as uniformly as possible, and the average value of the shortest distance between the intermetallic compounds is 100.
The average value of the shortest distances between the intermetallic compounds is preferably 3 μm or more, and particularly preferably 5 μm or more, in order to avoid embrittlement of the matrix. Therefore, according to yet another detailed feature of the method of the present invention, the average value of the shortest distance between the intermetallic compounds is set to 3 to 100 μm, particularly 5 to 50 μm.

According to the results of the experimental research conducted by the inventors of the present application,
The intermetallic compound may be an intermetallic compound of A1 and any one of the above metal elements, but it is particularly preferable that the intermetallic compound has a Vickers hardness of 300 or more, and is lower than the hardness of the reinforcing material. preferable. Therefore, according to another further detailed feature of the method of the present invention, the intermetallic compound has a Vickers hardness of 300 or more, which is set to a value lower than the hardness of the reinforcing material.

According to the results of the experimental research conducted by the inventors of the present application,
In order to further improve the wear resistance of the composite material particularly when the reinforcing material is short fibers or whiskers, the volume ratio of the intermetallic compound in the composite material is preferably 3 to 80%, It is particularly preferably 10 to 60%.
Therefore, according to yet another detailed feature of the method of the present invention, the volume fraction of intermetallic compound in the composite is 10-60%.
Is set to.

According to the results of the experimental research conducted by the inventors of the present application,
When the intermetallic compound is granular, the maximum particle size is 50
It is preferable that the intermetallic compound has a maximum length of 100 when the intermetallic compound is acicular.
It is preferably not more than μm, particularly preferably not more than 50 μm.

Further, the reinforcing material in the method of the present invention may be a reinforcing material of any material conventionally used for manufacturing a composite material, but a ceramic reinforcing material is higher than a reinforcing material made of metal or the like. Since strength, hardness, wear resistance improving effect, high temperature stability, etc. are excellent and reactivity with the molten metal of the matrix is low, ceramic short fibers, ceramic whiskers or ceramic particles are used as a reinforcing material in the present invention. It

In the present specification, “volume ratio of intermetallic compound in matrix” means 10 parts of the composite material other than the reinforcing material.
It means the volume percentage of the intermetallic compound when viewed as 0,
“Volume ratio of intermetallic compound in composite material” means the volume percentage of the intermetallic compound when the whole composite material is taken as 100.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Example 1 As shown in Table 1 below, alumina short fibers having an average fiber length of 3 mm and an average fiber diameter of 2 mm (95% A1 ₂ O ₃ , 5%
10% by volume of SiO ₂ , ICI's "Safir")
Ni powder having an average particle diameter of 5μ (purity 99%) is contained in volume ratios of 0%, 1%, 2%, 5%, 7%, 10%, 1 respectively.
Eight types of porous compacts containing 5% and 18% were formed by a suction molding method. In this case, each molded body had a cylindrical shape with a diameter of 100 mm and a height of 20 mm, and the fibers and powder were substantially uniformly mixed with each other.

Then, each molded body is preheated to 500 ° C. in nitrogen gas, and thereafter, as shown in FIG. 1, each molded body 10 is fixed to the bottom of the mold cavity 16 of the mold 14 of the high-pressure casting apparatus 12 by press fitting. And put it in the mold cavity
℃ aluminum alloy (JIS standard AC1A, 4.5%
A molten metal 18 containing Cu, 1% Si and the balance substantially A1) was poured, and the molten metal was pressurized to a pressure of 1000 kg / cm ² by a plunger 20, and the pressurized state was maintained until the molten metal was completely solidified. .

Then, composite materials No. 1 to 8 formed in the portion corresponding to the original molded body were cut out from the casting thus formed, and the microstructure of the cross section of each composite material was observed with a microscope.
Composite material No. 2 formed by using a compact containing powder
In No. 8, it was confirmed that the A1-Ni intermetallic compound was finely dispersed in the matrix. According to the X-ray diffraction test, this intermetallic compound is NiAl ₃ or NiA.
It was 1 ₃ and Ni ₂ Al ₃ , and it was confirmed by image analysis that the amount of intermetallic compound increased as the amount of Ni powder contained in the original compact increased. Table 1 below shows the types of intermetallic compounds formed in composite materials Nos. 1 to 8 and their volume ratios. 2 and 3 show the metallographic structure of the cross section of composite material No. 4 as 1
FIGS. 2A and 2B are micrographs showing magnifications of 00 and 400, respectively, and in FIGS. 2 and 3, white and gray portions are NiA1 ₃ portions, and black portions are alumina short fiber portions. .

Heat treatment T ₇ was applied to each composite material, and a disc-shaped adhesion test piece having a diameter of 90 mm and a thickness of 10 mm from each composite material, a tensile test piece having a parallel portion length and diameter of 14 mm, 16 × Abrasion test specimens having 6 × 10 mm dimensions were formed. Then, these test pieces were subjected to an adhesion test and a tensile test at 250 ° C. and a wear test at room temperature.

The adhesion test is based on stainless steel (JIS standard SUS440A
(18% Cr, 0.5% Mo, 0.7% C, balance Fe)
C-shaped mating material having an outer diameter of 82 mm, an inner diameter of 76 mm and a height of 2 mm is repeatedly pressed against each adhesion test piece at 250 ° C., 10 Hz, 5 mm stroke for 30 minutes at a pressure of 10 kgf / cm ^2. After the test is completed, the area of the adhesion part generated in each test piece is measured by image analysis, and the area (mm ² ) of the adhesion part generated in the contact area between the test piece and the mating material is obtained. It was

The tensile test was carried out by performing a normal tensile test at 250 ° C., and dividing the maximum load withstood by the test piece, that is, the tensile load by the original cross-sectional area of the parallel portion to obtain the tensile strength.

In addition, the wear test is 35mm outside diameter, 30mm inside diameter
Carburized and quenched bearing rope with a width of 10 mm (surface hardness Hv72
Each wear test piece was brought into contact with the outer peripheral surface of the cylindrical test piece made of 0), and a contact surface pressure of 60 was obtained while supplying lubricating oil (SAE 10W-30) at room temperature (20 ° C.) to the contact portion of the test piece.
It was carried out by rotating a cylindrical test piece for 1 hour at kg / mm ² and a sliding speed of 0.3 m / sec.

The results of these tests are shown in FIGS. 4 to 6, respectively. In FIG. 6, the upper half represents the wear amount (wear depth μm) of the wear test piece, and the lower half represents the wear amount (wear loss mg) of the cylindrical test piece as the mating material. (The same applies to FIGS. 13, 21 to 23 and 25 described later).

From FIG. 4, it can be seen that the area where adhesion occurs is remarkably reduced when the volume ratio of the intermetallic compound in the matrix is 5% or more, particularly 10% or more. Further, from FIG. 5, it is understood that the tensile strength of the composite material becomes a relatively high value when the volume ratio of the intermetallic compound in the matrix is 5 to 70%, particularly when it is about 10 to 40%. Further, from FIG. 6, the volume ratio of the intermetallic compound in the matrix is 5 to 70%, particularly 1
It can be seen that the wear amount of the composite material and the mating material becomes a small value in the case of about 0 to 55%. Therefore, from the results of these tests, in order to obtain a composite material excellent in adhesion resistance, strength and wear resistance, the volume ratio of the intermetallic compound in the matrix is 5
It is understood that it is preferably 70%, especially 10% to 40%.

Example 2 As shown in Table 2 below, N contained in the molded body
The volume ratio of the i powder is set to 0% and 3%, and an aluminum alloy for spreading (JIS standard 7075, 5.5% Zn, 2.5% Mg, 1.5% is used as an alloy to be filled in the molded body. C
u, balance A1), aluminum alloy for casting (JIS standard AC8, 12% Si, 1% Cu, 1% Mg, 1% N)
i), Aluminum alloy for die casting (JIS standard AD
C10, 8% Si, 3% Cu and the balance A1) are used, and the temperatures of the melts of these alloys are 800 ° C. and 740, respectively.
Composite materials Nos. 9 to 14 were manufactured under the same procedure and conditions as in Example 1 except that the temperature was set to 720C.
Note that the composite material No. 9 was subjected to heat treatment T ₆ instead of heat treatment T ₇ .

Example 1 for each composite material thus produced
The kind and amount of the intermetallic compound contained in the matrix were measured in the same manner as in the above. As a result, as shown in Table 2, no intermetallic compound was present in the matrix of composite materials Nos. 9 to 11 produced without using the Ni powder, and 3% of the Ni powder was used. NiA in the matrix of the composite materials No. 12 to 14 produced by
1 ₃ was present at about 18% finely dispersed state by volume.

Further, each composite material manufactured as described above was subjected to an adhesion test and a tensile test at 250 ° C. under the same procedure and conditions as in Example 1. The results of these tests are shown in FIGS. 7 and 8, respectively.

From FIG. 7, even when the matrix metal is an aluminum alloy other than JIS AC1A, the adhesion resistance of the composite material in which the intermetallic compound in the matrix is finely dispersed shows that the matrix contains the intermetallic compound. It turns out that it is far superior to the conventional composite material which is not. Further, from FIG. 8, it is understood that the composite material in which the intermetallic compound is finely dispersed in the matrix has the strength equal to or higher than that of the conventional composite material in which the intermetallic compound is not contained in the matrix.

Further, from the results of these tests, the matrix may be an alloy containing A1 as a main component, for example, JIS standard 201.
5, 3003, 4043, 5052 and other wrought aluminum alloys, JIS standard AC2B, AC4C, AC7A and other cast aluminum alloy alloys, JIS standard ADC1,
It is presumed that similar results can be obtained in the case of aluminum alloys for die casting such as ADC3 and ADC7.

Example 3 As shown in Table 3 below, alumina-silica short fibers (55% A1 ₂ O ₃ , 45% SiO ₂ ) having an average fiber length of 3 mm and an average fiber diameter of 3 μm were used in place of the alumina short fibers, fibers. Silicon carbide whiskers (98% β-SiC) with a length of 10 to 200 μm and a fiber diameter of 0.05 to 1 μm, an average particle diameter of 1 μm
Of silicon nitride particles (99% α-Si ₃ N ₄ ) of 10%, 15% and 30% by volume, respectively, and Ni powder of 0%.
%, 5%, 6 types of compacts are formed, and aluminum alloy (JIS standard 5056, 5
% Ng, 0.4% Fe, 0.3% Si, 0.1% Cu,
Composite materials Nos. 15 to 20 were manufactured under the same procedure and conditions as in Example 1 except that the balance A1) was used and the temperature of the molten metal was set to 800 ° C. The heat treatment applied to each composite material is not heat treatment T ₇ , but 400
It was a heat treatment of heating at 0 ° C. for 3 hours and then cooling the furnace.

Example 1 for each composite material thus produced
The kind and amount of the intermetallic compound contained in the matrix were measured in the same manner as in the above. As a result, as shown in Table 3, no intermetallic compound was present in the matrix of composite materials Nos. 15 to 17 manufactured without using the Ni powder, and 5% of the Ni powder was used. Ni in the matrix of composite materials No. 18 to 20 manufactured by
A1 ₃ is present in a state which is approximately 30% finely dispersed by volume.

Further, each composite material manufactured as described above was subjected to an adhesion test and a tensile test at 250 ° C. under the same procedure and conditions as in Example 1. The results of these tests are shown in FIGS. 9 and 10, respectively.

From FIG. 9, even when the reinforcing material is other than alumina short fiber,
It can be seen that the adhesion resistance of the composite material in which the intermetallic compound is finely dispersed in the matrix is far superior to that of the conventional composite material containing no intermetallic compound in the matrix. Further, from FIG. 10, it is understood that the composite material in which the intermetallic compound is finely dispersed in the matrix has strength equal to or higher than that of the conventional composite material in which the intermetallic compound is not contained in the matrix.

The results of these tests also show that the reinforcing material may be either fibers or particles. Also, from the results of these tests, the reinforcing material is excellent in strength and hardness, stable even at high temperature, has excellent wear resistance, and has low reactivity with the molten aluminum alloy. For example, so-called chopped fibers obtained by cutting glass fibers, alumina long fibers, silicon carbide long fibers, Si-Ti-C long fibers and the like into short fibers, and whiskers such as silicon nitride whiskers, alumina whiskers and potassium titanate whiskers. It is presumed that particles such as alumina particles, zirconia particles, silicon carbide particles, tungsten carbide particles, and boron nitride particles may be used.

Example 4 As shown in Table 4 below, a fiber length of 50 to 300 μm and a fiber diameter of 0.1 to 0.5 μ were used instead of alumina short fibers.
m silicon nitride whiskers (97% α-Si ₃ N ₄ ) in a volume ratio of 10%, and an average particle size of 5 instead of Ni powder.
μm Fe powder (purity 99%), Co with an average particle size of 5 μm
Powder (purity 99%), Mn powder with an average particle size of 10 μm (purity 98%), Ti powder with an average particle size of 8 μm (purity 99%)
4 types of molded bodies containing 5%, 3%, and 7% by volume respectively, and a molded body made only of silicon nitride whiskers with a volume ratio of 10% are formed.
Aluminum alloy at 0 ° C (JIS standard AC5A, 4% C
A composite material containing an intermetallic compound finely dispersed in a matrix under the same procedure and conditions as in Example 1 except that u, 1.5% Mg, 2% Ni, and the balance A1) were used. No. 22 to 25 and composite material N containing no metal compound
o.21 was produced.

Example 1 for each composite material thus produced
The kind and amount of the intermetallic compound contained in the matrix were measured in the same manner as in the above. As a result, as shown in Table 4, the intermetallic compound was not present in the matrix of the composite material No. 21, and the composite material No. 22
FeA1 ₃ and Co in the matrix of ~ 25
₂ A1 ₉ , MnA1 ₆ and TiA1 ₃ are each about 30%
It existed in a finely dispersed state.

Each composite material produced as described above was subjected to an adhesion test and a tensile test at 250 ° C. under the same conditions and conditions as in Example 1 and a wear test at room temperature. The results of these tests are shown in FIGS. 11 to 13, respectively.

From FIGS. 11 and 13, the intermetallic compound is FeA1 ₃
, Etc., the adhesion resistance and friction and wear properties of the composite material in which the intermetallic compound is finely dispersed in the matrix are far superior to those of the conventional composite material containing no intermetallic compound in the matrix. I understand that. Also the 12th
From the figure, it is understood that the composite material in which the intermetallic compound is finely dispersed in the matrix has the strength equal to or higher than that of the conventional composite material containing no intermetallic compound in the matrix.

Further, as shown in Table 8 below, as a material for forming the intermetallic compound, Cr powder, Mo powder, V powder,
Using W powder, Ta powder, Nb powder, Zr powder, and Cu powder, a composite material in which an intermetallic compound having a volume ratio of about 30% is finely dispersed in a matrix is produced, and the composite material is manufactured. An adhesion test at 250 ° C. was conducted under the same conditions and conditions as in Example 1, and as shown in Table 8, even when the intermetallic compound was CrA ₁₇ etc., the conventional composite material was used. It was confirmed that excellent adhesion resistance was obtained as compared with.

From the results of these tests, the intermetallic compound to be formed in the matrix is the same as the above refractory metal element and A1.
It will be understood that an intermetallic compound with or a combination thereof may be used. Each of these intermetallic compounds has a Vickers hardness of more than 200 at 250 ° C. and is extremely excellent in heat resistance.

Example 5 As shown in Table 5 below, 30% by volume of A1 ₂ O ₃ particles (99% α-A1 ₂ instead of alumina short fibers were used.
Fe-Mn alloy powder (50% Fe, containing O ₃ and an average particle size of 1 μm) and having a volume ratio of 3% in place of the Ni powder.
50% Mn, average particle size 10 μm), N with a volume ratio of 1.6%
i-Fe alloy powder (50% Ni, 50% Fe, average particle size 10 μm), Ni—Cu alloy powder (5% by volume) of 7.8%
Cu-Zn powder (70% Cu, 30% Zn, 0% Ni, 50% Cu, average particle diameter 10 μm) and volume ratio 9.3%.
A molded body containing an average particle size of 10 μm) and a molded body composed of only A1 ₂ O ₃ particles having a volume ratio of 30%,
An aluminum alloy with a hot water temperature of 720 ° C (J
Composite material No. containing an intermetallic compound finely dispersed in a matrix under the same procedure and conditions as in Example 1 except that IS standard ADC7, 5% Si, and the balance substantially A1) were used. Composite material No. 26 containing no .27 to 30 and no intermetallic compound was produced.

Example 1 for each composite material thus produced
The kind and amount of the intermetallic compound contained in the matrix were measured in the same manner as in the above. As a result, as shown in Table 5, no intermetallic compound was present in the matrix of the composite material No. 26 produced without using the alloy powder, and the alloy powder was produced using 3% of the alloy powder. In the matrixes of the composite materials Nos. 27 to 30 thus prepared, the corresponding intermetallic compounds were present in a finely dispersed state in a volume ratio of about 30%.

Further, each composite material manufactured as described above was subjected to an adhesion test and a tensile test at 250 ° C. under the same procedure and conditions as in Example 1. The results of these tests are shown in FIGS. 14 and 15, respectively.

From FIG. 14, even when the metal for forming the intermetallic compound is an alloy and therefore the intermetallic compound is a complex intermetallic compound, the composite material in which the intermetallic compound is finely dispersed in the matrix is obtained. It can be seen that the anti-adhesion properties of are much superior to conventional composites that do not contain intermetallic compounds in the matrix. Further, from FIG. 15, it is understood that the composite material in which the composite intermetallic compound is finely dispersed in the matrix also has the strength equal to or higher than that of the conventional composite material containing no intermetallic compound in the matrix. .

Further, from the results of these tests, the intermetallic compounds dispersed in the matrix of the composite material are Ni, Fe, Co and M.
n, Ti, Cr, Mo, V, W, Ta, Nb, Ti, Z
Two types of refractory metals such as r, Be and Cu, and A1
It is understood that a complex intermetallic compound with

Example 6 As shown in Table 6 below, glass fiber having a volume ratio of 5% (25% A1 ₂ O ₃ , 10%) was used instead of the alumina short fiber.
MgO, balance substantially SiO ₂ , average fiber diameter 10 μm,
The average fiber length is 5 mm), and the average particle diameter is 200 μm, 150 μm, 100 μm, 90 μ instead of Ni powder.
m, 60 μm, 30 μm, 5 μm, a compact containing 5% by volume Fe powder (purity 99%) and a compact consisting only of 5% by volume glass fiber were formed, and the melt temperature of the alloy was 740 ° C. Aluminum alloy (JIS standard AC4C,
An intermetallic compound finely dispersed in the matrix was prepared according to the same procedure and conditions as in Example 1 except that a melt of 7% Si, 0.3% Mg and the balance substantially A1) was used. Composite materials No. 32 to 38 containing and composite material No. 31 containing no intermetallic compound were manufactured.

Example 1 for each composite material thus produced
The kind, the amount, and the size of the intermetallic compound contained in the matrix were measured in the same manner as the case. As a result, as shown in Table 6, no intermetallic compound was present in the matrix of the composite material No. 31 manufactured without using the Fe powder, and the F particles having an average particle diameter of 30 μm or less were obtained.
Composite materials No. 37 and 38 produced using e-powder
FeA1 ₃ is present in a finely dispersed state in the matrix of FeA1 _{3 in} the matrix of the composite materials No. 32 to 36 manufactured using Fe powder having an average particle size of 60 μm or more. Was finely dispersed, but it was confirmed that pure Fe remained in the central portion.
So the composite material according pure Fe remains is subjected to a heat treatment of holding for 50 hours them to 500 ° C., allowed to fully convert into FeA1 ₃ a Fe remaining thereby.
F existing in the matrix of composite materials No. 32 to 38
The volume ratio of eA1 ₃ is about 28%, and the average diameter of each is 250 μm, 200 μm, 130 μm, 120 μm, 8 μm.
It was 0 μm, 40 μm, and 7 μm.

Further, heat treatment T _{7 is} applied to each composite material manufactured as described above.
The same procedure and conditions as in Example 1
An adhesion test at 0 ° C was performed. The results of these adhesion tests are shown in FIG.

It can be seen from FIG. 16 that the smaller the average value of the shortest distances of the intermetallic compounds is, the more the adhesion resistance of the composite material is improved, and especially when the average value of the shortest distances of the intermetallic compounds is 100 μm or less,
It can be seen that the adhesion generation area is significantly reduced when the thickness is 0 μm or less and further when it is 50 μm or less.

Further, when the adhesion state of each test piece was investigated in detail after the adhesion test, it was confirmed that the adhesion occurred in the A1 portion around the intermetallic compound and spreads over the entire contact surface of the test piece. It was It was also found that even if the volume ratios of the formed intermetallic compounds were the same, the more uneven the dispersion state, the more easily the adhesion occurred.

17 and 18 show the intermetallic compound FeA1.
_{3 has} an average diameter of 250 μm and 40 μm, and the average values of the shortest distances between the intermetallic compounds are 150 μm and 25 μ, respectively.
It is a schematic diagram which shows the structure of the cross section of composite material No. 32 and No. 36 which are m. Note At a these figures, 22 denotes an intermetallic compound FeA1 _3, 24 denotes a glass fiber, 26 denotes a matrix. As can be seen from the comparison of these figures, the shortest distance between the intermetallic compounds becomes smaller as the diameter of the intermetallic compounds becomes smaller, and the structure becomes more uniform as the diameter of the intermetallic compounds becomes smaller.

In this example, in order to keep the volume ratio of the intermetallic compound constant and to keep its size (that is, the distance between the intermetallic compounds) constant, the average particle diameter of the Fe powder was relatively large. by this heat treatment to hold 50 hours 500 ° C. for, but was converted to pure Fe in FeA1 _3, intermetallic compound itself need not be one type. For example, as long as the intermetallic compound in the outermost layer is an intermetallic compound having higher heat resistance than the matrix, the intermetallic compound dispersed in the matrix is, for example, as shown in FIG. It may have a multi-layered structure, or as shown in FIG. 20, may have a multi-layered structure composed of several kinds of metal compound layers and a pure metal at the center.

Example 7 Silicon carbide whiskers (98% β-Si) having a fiber length of 10 to 200 μm, a fiber diameter of 0.05 to 1 μm, and a hardness of Hv3300.
C) and Ni powder having an average particle size of 3 μm (purity 99%) are mixed at a volume ratio of 2: 1 and compression molding is performed to form a columnar shape having a diameter of 100 mm and a height of 20 mm, and whiskers. And Ni powder had volume ratios of 10% and 5%, respectively, and formed a substantially uniformly mixed molded body.

Then, preheat this molded body to 300 ° C. in nitrogen gas,
Aluminum alloy with a hot water temperature of 760 ℃ (J
Composite material No. 40 was manufactured under the same procedure and conditions as in Example 1 except that a molten metal of IS standard AC8A) was used, and the same was applied using a molded body containing no Ni powder. Composite material No. 39 was manufactured.

Further, as shown in Table 7, instead of Ni powder, Mg powder having an average particle size of 20 μm, Cu powder having an average particle size of 10 μm,
Composite materials No. 41 to 45 were manufactured under the same procedure and conditions by using the average particle size of 5 μm Cr powder, the average particle size of 3 μm Fe powder and the average particle size of 10 μm Ti powder.

Example 1 for each composite material thus produced
The kind, amount and hardness of the intermetallic compound contained in the matrix were measured in the same manner as in the above. As a result, as shown in Table 7, the intermetallic compound did not exist in the matrix of the composite material No. 39, and the composite material N
A1 ₃ Ni in the matrix of o.40 to 45
(And very small amount of A1 ₃ Ni ₂ , A1Ni), Mg ₂ A
1 ₃ , CuA1 ₂ , CrA1 ₇ , FeA1 ₃ , TiA1
₃ (Each hardness Hv950, 190, 330, 37
0, 550, 740) was present in an amount of about 30% (volume ratio of intermetallic compound in the composite material).

Example 1 for each composite material manufactured as described above
A wear test was performed at room temperature under the same procedure and conditions as in the above. The results of these abrasion tests are shown in FIG.
In FIG. 21, the horizontal axis represents the hardness of the intermetallic compound (Vickers hardness).

As shown in FIG. 21, when the hardness of the intermetallic compound is 300 or more, the wear amount of the mating material is significantly reduced, and the wear resistance of the composite material itself is lower than that when the hardness of the intermetallic compound is less than 300. You can see that it will improve.

From the results of this test, the intermetallic compound dispersed in the matrix has a hardness Hv of 300 in order to improve the wear resistance of the composite material and the friction and wear characteristics with respect to the mating material.
More intermetallic compounds such as _Ni 2 _A1 3, FeA
1 ₆ , MnA1 ₆ , ZrA1 ₃ , Co ₂ A1 ₉ , MoA
1 ₃ , (CuNi) ₂ A1 ₃ , (FeSi) A1 ₅ ,
(CuFeMn) presumably is preferably A1 ₆ like.

Example 8 In the composite material 40 of Example 7, a composite material 40 was used except that various ceramic fibers as shown in Table 10 were used as the fibers contained in the molded body instead of the silicon carbide whiskers. Composite material N under the same procedure and conditions
o.47-54 were produced.

For the purpose of comparison, composite materials Nos. 47 'to 54' were manufactured under the same procedures and conditions as those of the composite materials Nos. 46 to 54 except that a molded body containing no Ni powder was used.

Then, these composite materials were subjected to a wear test at room temperature under the same conditions and conditions as in Example 1. The results of these abrasion tests are shown in FIG. Incidentally, in FIG. 22, the horizontal axis represents the Vickers hardness Hv of the reinforcing fiber.

From FIG. 22, it is understood that the amount of wear of the composite material itself is smaller when the intermetallic compound is finely dispersed in the matrix, regardless of the hardness of the reinforcing fiber. Further, when the reinforcing fiber is a ceramic fiber which has been conventionally used for improving the wear resistance of a metal material such as a hardness of Hv500 or more, a composite material in which an intermetallic compound is finely dispersed in a matrix is used. It can be seen that the aggressiveness to the mating material is significantly smaller than that of the composite material in which the intermetallic compound is not dispersed in the matrix, and the friction and wear characteristics to the mating material are excellent regardless of the hardness of the reinforcing fiber.

Example 9 The same procedure as in Example 7 except that 10 kinds of molded bodies were formed by setting the amount of Ni powder contained in the molded body to various values, and these molded bodies were used. Composite materials Nos. 55 to 64 were manufactured under the above conditions, and a wear test was carried out at room temperature under the same conditions and conditions as in Example 1 for each composite material. The volume ratios of the intermetallic compounds in the composite materials No. 55 to 64 are 3%, 5%, 10%, 20%,
It was 30%, 40%, 50%, 60%, 70%, 80%. The results of these wear tests are shown in FIG. 23 together with the results of the wear test of composite material No. 39. In FIG. 23, the horizontal axis represents the volume ratio of A1-Ni intermetallic compound in the composite material.

From FIG. 23, the volume ratio of the intermetallic compound in the composite material is 3
When it is -80%, the friction and wear characteristics are improved as compared with the conventional composite material (No. 39), and it is particularly preferable that the volume ratio of the intermetallic compound in the composite material is about 10-60%. I understand.

The intermetallic compound has the Vickers hardness H shown in Example 7.
The results showing the same tendency as the results shown in FIG. 23 were obtained also in the case of various compounds having v300 or higher.

Comparative Example A compact containing 30% by volume of the same alumina short fibers as those used in Example 1 but no Ni powder, a three-dimensional network structure made of Ni (porosity 90%,
Cell size 0.3 mm), containing 10% by volume of the same alumina short fibers as the alumina short fibers used in Example 1, in place of Ni powder, NiO powder (average particle size 2 μm, purity 99%). Composite materials A, B, and C were manufactured under the same procedures and conditions as in Example 1, except that a molded body containing 8% by volume was used. Then, with respect to each of the composite materials thus produced, the kind and the like of the intermetallic compound contained in the matrix were determined in the same manner as in Example 1. As a result, no intermetallic compound was present in the matrix of the composite material A, and in the composite material B, only A1 ₃ Ni (and a very small amount of A
1 ₃ Ni ₂ , A1Ni) was present, and A1 ₃ Ni and A1 ₂ O ₃ were present in the matrix of the composite material C in a finely dispersed state. In this case composite material C
It is speculated that NiO was reduced by A1 in the matrix to produce intermetallic compounds A1 ₃ Ni and A1 ₂ O ₃ in the manufacturing process of. Composite material C
Of A1 ₃ Ni and A1 ₂ O ₃ contained in the matrix of
The volume ratio was 30% and 7.4% based on the matrix.

Example 1 for each composite material manufactured as described above
The adhesion test at 250 ° C. and the wear test at room temperature were conducted under the same procedure and conditions as in the above. The results of these tests are shown in FIGS. 24 and 25, respectively, together with the results of composite material No. 4.

It can be seen from FIG. 24 that the composite material No. 4 of the present invention has much higher adhesion resistance than the composite materials A and B, and has the same adhesion resistance as the composite material C. Further, it can be seen from FIG. 25 that the composite material No. 4 of the present invention is far superior in frictional wear characteristics to the composite material C and is superior in frictional wear characteristics to the composite materials A and B.

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

[Brief description of drawings]

FIG. 1 is a sectional view showing a high pressure casting step in one embodiment of the method for producing a composite material according to the present invention, FIG. 2 and FIG.
Figure microscope true illustrating manufactured of one embodiment of a composite cross-section of the metallic structure at 100-fold, respectively, and 400-fold in accordance with the present invention the intermetallic compound NiA1 ₃ is finely dispersed, Figure 4 to 6 The figures show the adhesion test at 250 ° C. performed on each composite material of Example 1, 250 ° C.
Graphs showing the results of the tensile test at room temperature and the abrasion test at room temperature, and FIGS. 7 and 8 show the results of the adhesion test at 250 ° C. and the tensile test performed on the composite material of Example 2, respectively. FIG. 9 and FIG. 10 are graphs showing the results of the adhesion test and the tensile test at 250 ° C. performed on the composite material of Example 3, respectively, and FIGS. Graphs showing the results of the adhesion test at 250 ° C., the tensile test at 250 ° C., and the wear test at room temperature performed on the composite material of Example 4, FIGS. 14 and 15 are those of Example 5. FIG. 16 is a graph showing the results of the adhesion test and the tensile test at 250 ° C. performed on the composite material, and FIG. 16 shows the results of the adhesion test at 250 ° C. performed on the composite material of Example 6 between metals. Shortest between compounds Graph showing the mean value of the release abscissa, intermetallic compounds diagram 17 and FIG. 18 respectively Fe
A1 ₃ having an average particle diameter of 250 [mu], a 40 [mu, 150 [mu] m average value of the shortest distance between the intermetallic compounds, respectively, 25
FIG. 19 is a schematic view showing a cross-sectional structure of the composite material having a thickness of
FIGS. 20 and 20 are each a solution diagram showing an intermetallic compound having a multilayer structure, and FIG. 21 is a graph showing the results of an abrasion test performed on the composite material of Example 7 with the hardness of the intermetallic compound as the horizontal axis. FIG. 22 is a graph showing the results of the abrasion test conducted on the composite material of Example 8 with the hardness of the reinforcing fiber as the horizontal axis, and FIG. 23 shows the results of the abrasion test conducted on the composite material of Example 9. Graphs showing the volume ratio of the A1-Ni intermetallic compound in the composite material on the horizontal axis, FIGS. 24 and 25 are respectively the adhesion test at 250 ° C. and the room temperature at room temperature performed on the composite material of the comparative example. 3 is a graph showing the results of the abrasion test together with the results of one example of the composite material of the present invention. 10 ... Molded body, 12 ... Casting device, 1
4 ... Mold, 16 ... Mold cavity, 18 ... Matrix melt, 20 ... Plunger, 22 ... Intermetallic compound F
eA1 ₃ , 24 ... Glass fiber, 26 ... Matrix

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Fuwa 1 Toyota-cho, Toyota-cho, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Hirofumi Michioka 1-cho, Toyota-cho, Aichi Prefecture Toyota Motor Co., Ltd. (56) References JP-A 61-163250 (JP, A) JP-A 61-163249 (JP, A) JP-A 61-104037 (JP, A) JP-A 1-205041 (JP, A) Kaihei 1-152229 (JP, A) JP 63-312901 (JP, A) JP 1-230737 (JP, A)

Claims (1)

[Claims] 1. A method for producing an aluminum alloy-based composite material comprising aluminum alloy as a matrix and ceramic short fibers, ceramic whiskers or ceramic particles as a reinforcing material, comprising the reinforcing material and Fe, Ni, Co, Cr, C.
to form a porous compact comprising a substantially uniform mixture with fine particles of at least one metal element selected from the group consisting of u, Mn, Mo, V, W, Ta, Nb, Ti and Zr. A molten aluminum alloy is infiltrated into the compact, and then the molten metal is solidified, thereby substantially forming an intermetallic compound of A1 and at least one metal element in the matrix between the reinforcing materials. A method for producing an aluminum alloy-based composite material, wherein the volume ratio of the intermetallic compound in the matrix is 5 to 70%.