JPS6353230A - Sliding member - Google Patents

Abstract

PURPOSE:To improve wear resistance by constituting either of relatively sliding members of a silicon-nitride whisker- and grain-reinforced metallic composite material and also by constituting the other of a nitrided steel having the prescribed hardness. CONSTITUTION:In the mutually abutting and relatively sliding sliding members, mutual sliding surface parts are formed of the prescribed composite material and the nitrided steel having a hardness Hv(50g) of >=550, respectively. In the above composite material, >=1vol% mixture of silicon-nitride whiskers and silicon-nitride grains is used as reinforcement, and a metal selected from Al, Mg, Sn, Cu, Pb, Zr, and alloys composed principally of the above elements is also used as matrix. Further, a part of the above reinforcement has an echinoid shape and has a diameter as a whole of <=220mu.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a sliding member consisting of two members that are in contact with each other and slide relative to each other, and more specifically, one member is made of silicon nitride whiskers. The present invention relates to a sliding member made of two members, one made of a composite material whose reinforcement is a mixture of particles and a sea urchin-like reinforcing material, and the other made of nitrided steel.

BACKGROUND OF THE INVENTION Special mechanical properties are often required in parts of the components and members of various machines. For example, in automobile engines, as demands for engine performance become higher, members such as pistons not only have excellent specific strength and rigidity, but also require that their sliding surfaces have excellent wear resistance. There is now a strong demand to be present. As a means of improving the specific strength, wear resistance, etc. of such members, attempts have been made to construct them from composite materials that have various inorganic fibers as reinforcements and light metals such as aluminum alloys as a matrix. ing.

As one such metal matrix composite material, the inventors of the present application have
Patent application filed by the same applicant as the applicant in 1988-
In this issue, a composite material is disclosed in which a mixture of silicon nitride whiskers and silicon nitride particles is used as a reinforcing material and a metal is used as a matrix, wherein at least a part of the reinforcing material is a sea urchin-like reinforcement material, that is, an aggregate of silicon nitride particles. We proposed a composite material that is a reinforcing material and consists of a large number of silicon nitride whiskers that protrude radially from the aggregate. Such composite materials can improve the specific strength, wear resistance, etc. of members made of them.

Problems to be Solved by the Invention However, in two sliding members that are in contact with each other and slide relative to each other, when one of the members is made of the above-mentioned composite material, the other member is Depending on the material of one member, the wear of the other member increases significantly, and therefore, they cannot be used as sliding members that abut each other and slide relative to each other.

The present inventors have proposed a sliding member consisting of two members that come into contact with each other and slide relative to each other, one of which is made of a composite material as described above, and the other member is nitrided. In order to minimize the amount of wear on both parts of sliding members made of steel, various studies have been carried out regarding the appropriate combination of materials and properties. As a result of experimental research, it was found that each type must have specific characteristics.

The present invention is based on the knowledge obtained as a result of the above-mentioned experimental research conducted by the inventors of the present invention, and one member is composed of silicon nitride whiskers (free whiskers) and particles (free particles) having excellent strength and rigidity. The composite material is made of a composite material in which the reinforcing material is a mixture of and a sea urchin-like reinforcing material, and a metal such as an aluminum alloy is used as a matrix, and the other member is made of nitrided steel. It is an object of the present invention to provide a sliding member consisting of two sliding members, which has improved wear resistance on the sliding surfaces of both members relative to each other.

Means for Solving the Problems According to the invention, the above-mentioned objects abut each other (
The sliding member includes a first member and a second member that slide in a sealing manner, and at least the sliding surface portion of the first member relative to the second member is made of silicon nitride whiskers and silicon nitride particles. A composite material whose matrix is a metal selected from the group consisting of aluminum, magnesium, tin, copper, lead, zinc, and alloys containing these as main components, wherein at least one of the reinforcing materials A portion of the second member is made of a composite material that is a sea urchin-shaped reinforcement material, and at least the sliding surface of the second member relative to the first member is made of nitrided steel with a hardness of Hv (50 g) 550 or more. This is achieved by a sliding member characterized in that it is configured as follows.

Effects and Effects of the Invention According to the present invention, at least a part of the reinforcing material of the composite material constituting the first member is a sea urchin-like reinforcement material, and the sea urchin-like reinforcement material is a silicon nitride particle aggregate in the center. and a large number of silicon nitride whiskers protruding radially from the particle aggregate, and the whiskers are firmly held in a substantially three-dimensionally randomly oriented state by the particle aggregate. As is clear from the results of experimental studies conducted by researchers, it has superior wear resistance compared to composite materials whose reinforcement is a simple mixture of silicon nitride whiskers and silicon nitride particles, and The component is Hv (50g) 5
Constructed of 50 or more nitrided steel. Therefore, according to the present invention, there is provided a sliding member consisting of two members that come into contact with each other and slide relative to each other, and the sliding surfaces of both members relative to each other have excellent wear resistance. A sliding member can be obtained in which the amount of wear on the respective sliding surfaces of both members can be minimized, and one of the members has excellent specific strength and rigidity.

According to the results of experimental studies conducted by the inventors of the present application, the volume fraction of the reinforcement made of a mixture of silicon nitride whiskers, particles, and sea urchin-like reinforcement is 1% or more, particularly 2% or more, and even 3% or more. % or more, the amount of wear of the composite material and the mating material can be suppressed to a low value. According to one detailed feature of the invention, therefore, the volume fraction of the reinforcing material is at least 2%, preferably at least 3%, more preferably at least 4%.

Also, according to the results of experimental research conducted by the inventors of the present application,
When the overall diameter of the sea urchin-shaped reinforcement exceeds 220μ, the amount of wear of the composite material and the mating material becomes relatively high. According to another detailed feature of the invention, therefore, the overall diameter of the sea urchin-shaped reinforcement is set to be less than or equal to 220 microns.

Also, according to the results of experimental research conducted by the inventors of the present application,
When the ratio between the diameter of the particle aggregate at the center of the sea urchin-shaped reinforcement and the length of the whiskers radially protruding from this is less than 1/10 or exceeds 2, the amount of wear of the composite material and the mating material is reduced. The value will be relatively high. Therefore, according to yet another detailed feature of the invention, the value of the ratio between the diameter of the particle aggregate at the center of the sea urchin-shaped reinforcement and the length of the whiskers radially projecting from this is 1/10 to 2. is set to

Also, according to the results of experimental research conducted by the inventors of the present application,
If the amount of sea urchin-like reinforcement contained in the reinforcement is less than 20vt%, the amount of wear of the composite material and the mating material will be relatively high. According to yet another detailed feature of the invention, therefore, the amount of sea urchin-like reinforcement relative to the total reinforcement is 20 wt%.
It is set as above.

Furthermore, according to the results of experimental research conducted by the inventors of the present application,
The total amount of particles and the amount of free particles contained in the reinforcing material are each 9
If it exceeds 0wt% or 70wt%, the amount of wear of the composite material and the mating material will be relatively high.

According to yet another detailed feature of the invention, the amount of total particles and the amount of free particles contained in the reinforcing material are therefore 90% each.
vt% or less, set to 70vt% or less.

Furthermore, the patent application filed in 1986 by the same applicant as the applicant of the present application
-46293, Japanese Patent Application No. 60-94880, and Japanese Patent Application No. 60-263344 each disclose a composite material made of metal reinforced with mullite crystal-containing alumina-silica fibers and mineral fibers. Sliding members made of a combination of nitrided steel, sliding members made of a combination of nitrided steel and composite materials made of metal reinforced with alumina fibers and alumina-silica fibers, and silicon nitride whisker reinforcement A sliding member made of a combination of a metal composite material and nitrided steel is described.

Furthermore, in the April 1985 issue of the magazine "Functional Materials", an article entitled "New Manufacturing Process for Silicon Nitride Powder" describes a silicon nitride sea urchin-like reinforcement material and its manufacturing method.

The sliding member according to the present invention may be applied to sliding members of various mechanical devices, such as a cylinder and a piston of an automobile engine, a piston ring and a piston, and the like.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Example 1 In order to evaluate the wear resistance of a metal matrix composite material reinforced with a mixture of silicon nitride whiskers, silicon nitride particles, and silicon nitride sea urchin-like reinforcement, silicon nitride whiskers, silicon nitride particles, and nitride A composite material containing a mixture of silicon sea urchin-like reinforcements as a reinforcement material and an aluminum alloy as a matrix metal was manufactured by a high-pressure casting method, and a wear test was performed on the composite material.

First, a mixture of silicon nitride whiskers, particles, and sea urchin-like reinforcing material (manufactured by Ube Industries, Ltd., the average fiber diameter of the whiskers is 0.
1 μ, average fiber length of whiskers 10 μ, average diameter of particle aggregate in the center 3 μ, average particle size of each particle 0.1 μ, weight ratio of whiskers to particles 2:3, Im of sea urchin-shaped reinforcement material 60
By performing compression molding on silicon nitride whiskers (wt 96, free particle amount 24 wt 96, free whiskers 16 wt%, total particle amount 60 wt%), as shown in FIG. 10, silicon nitride whiskers 1 a % silicon nitride particles 1 b , and a sea urchin-shaped reinforcing material 1c of silicon nitride are uniformly mixed, the whiskers are oriented in a substantially three-dimensional random manner, the volume fraction of the total reinforcing material is 10%, and the molded body 2 of the reinforcing material has dimensions of 80 x 80 x 20 mm. Formed.

Next, after heating the molded body to 600°C, the mold cavity 4 of the mold 3 at 250°C is heated as shown in FIG.
aluminum alloy (730°C) is placed in the mold.
Quickly pour the molten metal 5 of JIS standard AC8A), and use the plunger 6 at about 200°C to pump the molten metal at 1500 kg/am.
Pressure was applied at a pressure of 2, and the pressurized state was maintained until the molten aluminum alloy completely solidified.

Next, as shown in FIG. 12, the outer diameter 110 ml and the height 50 ml including the thus obtained composite material 1'
A cylindrical solidified body of lffl is subjected to heat treatment T7, a composite material is taken out from the solidified body, and a 16×6
Five block test pieces of combinations A and -A5 were cut out, each having dimensions of 10 mm x 16 x and 10 mm as the test surface.

For the purpose of comparison, the above-mentioned block test piece A was prepared using silicon nitride whiskers (manufactured by Tateho Chemical Industry Co., Ltd., average fiber diameter 1μ, average fiber length 10μ).

~ A composite material in which whiskers were randomly oriented in two dimensions and randomly oriented in three dimensions at a volume ratio of 10% was produced under the same conditions as in the case of producing A5, and heat treatment T7 was performed, so that the whiskers were randomly oriented in three dimensions. Combination A6 from composite materials
A block test piece was cut out from the composite material in which the whiskers were two-dimensionally randomly oriented, and a block test piece of combination A7 with the test surface perpendicular to the two-dimensional random orientation plane and a block test of combination A8 parallel to the two-dimensional random orientation plane were conducted. A piece was cut out.

Next, each block test piece was sequentially set in a friction and wear tester and brought into contact with the outer circumferential surface of a mating member, a cylindrical test piece made of nitrided steel with various hardnesses, and the contact area of the test pieces was heated to room temperature. (20℃) while supplying lubricating oil (castle motor oil 5W-30), contact surface pressure 20 kg/
+11112) A wear test was conducted in which the cylindrical specimen was rotated for 1 hour at a sliding speed of 0°3 m/see. The combinations of block test pieces and cylindrical test pieces in these wear tests are shown in Table 1 below.
The composite designated as l 3 N4 reinforced AI alloy is a composite material reinforced with a mixture of silicon nitride whiskers and particles and sea urchin-like reinforcement.

Note: 1) JIS standard r6sUJ 22) JIS standard SUS420J2 The results of these wear tests are shown in Figure 1. In Figure 1, the upper half shows the wear amount (wear scar depth μ) of the block test piece.
, and the lower half represents the amount of wear (wear area Q mg) of the cylindrical test piece that is the mating material (see Figures 2 to 3 below).
The same applies to Figure 4).

From FIG. 1, the wear amount of the block test piece and cylindrical test piece of combinations A1-A4 is smaller than that of combinations A5, A6, and 88, and is substantially equal to or less than the wear amount of combination AI. Therefore, in order to reduce the amount of wear of both the composite material and the mating material, it is understood that the hardness of the nitrided steel of the mating material is preferably Hv (50 g) 550 or more. In addition, a comparison of the wear amount of the block test piece and the opposing material in the case of block test pieces AI and A8 reveals that there is a remarkable anisotropy in the wear resistance of the composite material when the whiskers are oriented in a two-dimensional random manner. I understand.

Example 2 In order to improve the friction and wear properties of a metal matrix composite material reinforced with a mixture of silicon nitride whiskers, silicon nitride particles, and silicon nitride sea urchin-like reinforcement, the volume fraction of the total reinforcement must be increased. In order to examine what value is appropriate, we set the volume percentage of the same reinforcing material as the reinforcing material containing the sea urchin-shaped reinforcing material used in Example 1 above to 0% and 1%.
, 2%, 3%, 4%, 5%, 15%, and 25%, and cylindrical test pieces made of nitrided stainless steel m (JIS standard 5US420J2) Hv800) were prepared in the same manner and conditions as in Example 1. A wear test was conducted using the material as a mating material. The results of these wear tests are shown in FIG.

From Figure 2, in order to reduce the amount of wear on the composite material and the mating material, the volume fraction of the total reinforcement should be 2% or more, especially 3% or more.
Furthermore, it is understood that the content is preferably 4% or more.

Example 3 When a silicon nitride sea urchin-like reinforcement is used as a reinforcing material, what is the appropriate value for the overall diameter of the sea urchin-like reinforcement in order to improve the friction and wear characteristics of the composite material? In order to examine whether this is the case, the following abrasion test was conducted.

First, 200 meshes, 100 meshes of the same sea urchin-like reinforcement material as that used in Example 1 above,
By passing through a 60 mesh and 50 mesh sieve,
The overall diameter is 75 μ or less, 75 to 140 μ, 14
The reinforcing materials were classified into five types: 0 to 200μ, 220 to 270μ, and 270μ or more, and molded bodies of the sea urchin reinforcement were formed by compression molding using each sea urchin reinforcement so that the volume fraction was 10%. Next, using each compact, an aluminum alloy (JIS standard ACIA) was formed into a matrix metal by high-pressure casting in the same manner as in Example 1 (molten metal temperature 710°C, pressure applied to the molten metal 1500 kg/a?). Composite materials were manufactured and heat treated T7, block test pieces were cut out from each composite material, and each block test piece was treated with stainless steel nitride (JIS standard 5US420J2)
A wear test was conducted under the same procedure and conditions as in Example 1 using a cylindrical test piece manufactured by 800) as a counterpart material. The results of these wear tests are shown in FIG. In FIG. 3, the numerical value shown below each bar graph indicates the overall diameter (unit: μ) of the sea urchin-shaped reinforcement.

From Figure 3, the overall diameter of the sea urchin-shaped reinforcement is 75μ.
Hereinafter, it can be seen that when the diameter is 75 to 140μ and 140 to 220μ, the wear amount of both the block test piece and the cylindrical test piece is low.

Therefore, in order to reduce the amount of wear on the composite material and the mating material, it is understood that the overall diameter of the sea urchin-shaped reinforcing material is preferably 220 μm or less.

Example 4 In Example 3, it was found that in order to reduce the amount of wear on the composite material and the mating material, it is preferable that the overall diameter of the silicon nitride sea urchin-shaped reinforcement is 220μ or less, so the sea urchin In order to examine the appropriate value for the ratio of the diameter of the particle aggregate at the center of the shaped reinforcement material to the length of the voice force protruding from this, the following wear test was conducted.

First, the silicon nitride sea urchin-like reinforcement material used in Example 1 above was passed through a 60-mesh sieve to remove sea urchin-like reinforcement materials with a total diameter of 220μ or more. The sea urchin-like reinforcing material is dispersed in water,
The overall diameter of the dispersion was 0.5 due to the filter.
Less than μ, 0°5~1μ, 1~5μ, 5~10μ, 10~
It was classified into 6 types of sea urchin-shaped reinforcement materials: 100μ and 100 to 220μ. Then, after drying the thus classified sea urchin-like reinforcements, 10 sea urchin-like reinforcements were arbitrarily selected for each group using a scanning electron microscope, and the average diameter of the particle aggregate in the center and protruding from this were randomly selected. The ratio of the average length of the whiskers was determined, and the value of the ratio D/L was determined. The results are shown in Table 2 below.

Table 2 Overall diameter (μ) DSL ratio value D/L0
．． 5 or less 4:1 4 0.5~1 2:1 21~5
1:1 1 5~10 1:4 1/410~100
1:10 1/10100~220 1:
15 1/15 Next, in the same manner and under the same conditions as in Example 1 above, a sea urchin-shaped reinforcement material of silicon nitride with a volume fraction of 10% was used as a reinforcement material, and an aluminum alloy (JIS standard IA C7A) was used as a matrix metal. Example 1 was prepared for each composite material and subjected to heat treatment T7.
Nitrided stainless steel fv4 in the same manner and conditions as in the case of
A wear test was conducted using a cylindrical test piece manufactured by (JIS Standard 5US420J2) HV800) as a mating material. The results of these wear tests are shown in FIG. The horizontal axis in Figure 4 is the ratio value D.
/L is shown on a logarithmic scale.

From Figure 4, when the ratio D/L of the diameter of the particle aggregate in the center and the length of the whisker protruding from this is 2 to 1/10, the wear amount of both the block test piece and the cylindrical test piece is It can be seen that is a small value.

Therefore, in order to reduce the amount of wear on the composite material and the mating material, the value D/L of the ratio between the diameter of the particle aggregate at the center of the sea urchin-shaped reinforcement and the length of the whisker protruding from this must be l/10~ 2
It can be seen that it is preferable that

Example 5 The matrix metal in Example 1 above was replaced with a magnesium alloy (JIS standard MD C1-A), the temperature of the molten magnesium alloy was set at 690 ° C,
By high-pressure casting in the same manner as in Example 1 except that the pressure applied to the molten metal was set at 1000 kHz/mm2, a mixture of silicon nitride whiskers, particles, and sea urchin-shaped reinforcement was used as a reinforcement material, and a magnesium alloy was formed. A composite material was manufactured in which the matrix metal was used as the matrix metal and the volume fraction of the reinforcing material was 10%. From the composite material, block test pieces B1 and B2 having the same dimensions as the block test piece of Example 1 were prepared with their test surfaces perpendicular to each other. It was cut out in the direction of For comparison purposes, block specimens A8 to A10 in Example 1 were made of magnesium alloy reinforced with silicon nitride whiskers oriented in a three-dimensional random manner and two-dimensionally randomly oriented, and the volume ratio of the whiskers was Block test piece B3 which is 1026~
A block test piece consisting only of B5 and magnesium alloy was prepared.

These block specimens were then tested in Example 1 above.
Nitrided stainless steel (J
A wear test was conducted using a cylinder test made of IS standard 5US420J2)Hv800) as a mating material. The results of these wear tests are shown in FIG.

In Fig. 5, the wear ratio of the block test piece is the percentage of the wear amount (wear scar depth) of each block test piece to the wear amount (wear scar depth) of the block test piece made only of magnesium alloy. It means.

From FIG. 5, it can be seen that the sliding member of the present invention has good friction and wear characteristics even when the composite material is a composite material having a magnesium alloy as a matrix metal.

Example 6 A mixture of silicon nitride whiskers, silicon nitride particles, and silicon nitride sea urchin-shaped reinforcement used in Example 1 above was used as a reinforcement (volume ratio of total reinforcement 1096), and a zinc alloy (JIS KIRAKU ZDCI), lead alloy (JIS KIRAKU WJ8
), a composite material having a tin alloy (JIS standard WJ 2) as the matrix metal was high-pressure casted in the same manner as in Example 1 (molten metal temperatures of 500°C, 410°C, and 330°C, respectively).
℃ and a pressure of 1000 kg/J) against the molten metal, and the block test pieces B1 and B in Example 5 were prepared from each composite material. ! Block specimens C1 and C2 corresponding respectively to Dl and R, , E, and E! ! It was created. For comparison purposes, corresponding to the block test pieces A8 to A1G in Example 1 described above, the volumes of whiskers made of each alloy reinforced with three-dimensionally randomly and two-dimensionally randomly oriented silicon nitride whiskers were also compared. Block test pieces consisting only of block test pieces C3 to C5, D3 to D5, E3 to E5 and each alloy with a ratio of 10% were formed.

These block specimens were then tested in Example 1 above.
The same procedure and conditions as in the case (however, the surface pressure is 5 kg /
mm”, test time 30 minutes) nitrided stainless steel!74
(JIS Standard 5US420J2) Hv800) A wear test was conducted using a cylindrical test piece made as a mating material.

The results of these wear tests are shown in FIGS. 6 to 8, respectively. In these figures, +j+! of the block specimen. Wear amount ratio by weight ratio means the percentage of the wear amount (wear scar depth) of each block test piece to the wear amount (wear scar depth) of a block test piece made only of the corresponding alloy.

From FIGS. 6 to 8, the sliding member of the present invention has good friction and wear characteristics even when the composite material is a composite material whose matrix metal is a zinc alloy, a lead alloy, or a tin alloy. I understand.

Example 7 The mixture of silicon nitride whiskers, silicon nitride particles, and silicon nitride sea urchin-like reinforcement used in Example 1 above, and the powder of copper alloy (10 wt% Sn, balance essentially Cu) were weighed. A small amount of ethanol was added to this and mixed for about 30 minutes in a Stark machine. After drying the mixture thus obtained at 80°C for 5 hours, a predetermined amount of the mixture was filled into a mold, and the mixture was punched at 4000 kg/a.
It was molded into a plate shape by compressing it at a pressure of n2. Next, each plate was heated at 770°C for 3 times in a batch-type sintering furnace set in an atmosphere of decomposed ammonia gas (dew point -30°C).
Sintering by heating for 0 minutes and slow cooling in a cooling zone in a sintering furnace to produce a composite material in which the volume fraction of the total reinforcement is 5% and the matrix metal is a copper alloy,
Block test pieces B1 and B2 of Example 5 were obtained from the composite material.
Block test pieces F1 and F2 corresponding to the above were created.

For comparison purposes, sintering was performed in the same manner and under the same conditions as the sintering method described above, except that the reinforcing material was replaced with the silicon nitride whiskers used in the comparative example of Example 1. A block test piece F3 made of a copper alloy in which silicon nitride whiskers were substantially three-dimensionally randomly oriented and had a whisker volume ratio of 5%, and a block test piece made only of a copper alloy were prepared.

These block test pieces were then subjected to an abrasion test using a cylindrical test piece made of nitrided stainless steel m (JIS standard F8SUS420J2) Hv800) as a counterpart material in the same manner and under the same conditions as in Example 1.

The results of these wear tests are shown in FIG. In Figure 9, the wear ratio of the block test piece is the percentage of the wear amount (wear scar depth) of each block test piece to the wear amount (wear scar depth) of the block test piece made only of copper alloy. It means.

From FIG. 9, it can be seen that the composite material of the present invention has good friction and wear characteristics even when a copper alloy is used as the matrix metal.

Although the present invention has been described above in detail in relation to the results of experimental research conducted by the inventors of the present invention, the present invention is not limited to these examples, and the present invention is not limited to these examples. It will be apparent to those skilled in the art that various other embodiments are possible within the scope.

[Brief explanation of drawings]

Figure 1 shows the combination of a composite material with a mixture of silicon nitride whiskers, silicon nitride particles, and silicon nitride sea urchin-like reinforcement as the reinforcement and an aluminum alloy as the matrix metal, and nitrided steel of various hardnesses. Graph showing the results of the wear test conducted in comparison with the results of the comparative example, 2nd
The figure shows the results of wear tests conducted on a composite material using a mixture of silicon nitride whiskers, silicon nitride particles, and silicon nitride bi-shaped reinforcement as the reinforcement, and an aluminum alloy as the matrix metal, using the volume fraction of the reinforcement as a parameter. The graph showing the results, Figure 3, is a combination of stainless steel and a composite material with silicon nitride sea urchin-like reinforcement as the reinforcement and aluminum alloy as the matrix metal, using the overall diameter of the sea urchin-like reinforcement as a parameter. Figure 4 is a graph showing the results of the wear test conducted on a composite material with a silicon nitride sea urchin-like reinforcement as the reinforcement material and an aluminum alloy as the matrix metal, and stainless steel. A graph showing the results of a wear test conducted using the ratio of the diameter of the particle aggregate to the average length of the whiskers protruding from this as a parameter. Graphs showing the results of wear tests conducted on the combination of nitrided stainless steel and a composite material in which a mixture of shaped reinforcements is used as a reinforcement material and a magnesium alloy is used as a matrix metal, in comparison with the results of comparative examples. Figure 8 shows the combination of nitrided stainless steel and a composite material whose reinforcement is a mixture of silicon nitride whiskers, silicon nitride particles, and silicon nitride sea urchin-like reinforcement, and whose matrix metals are zinc alloy, lead alloy, and tin alloy. Figure 9 is a graph showing the results of the wear tests compared with the results of comparative examples. A graph showing the results of a wear test conducted on the combination of a composite material and nitrided stainless steel in comparison with the results of a comparative example. FIG. 11 is an illustration showing the procedure for high-pressure casting using the molded material shown in FIG. 10, and FIG. FIG. 3 is a perspective view showing a solidified body obtained by high-pressure casting. 1a...Silicon nitride whiskers, lb...Silicon nitride particles, lc...Silicon nitride sea urchin-shaped reinforcement, 2...
Molded body, 3... Mold, 4... Mold cavity,
5... Molten metal, 6... Plunger patent applicant: Toyota Motor Corporation representative
Attorney Masaki Akashi, Patent Attorney Figure 1, Figure 3, Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figure 10, Figure 12, Figure 11 (self-initiated) 1. Indication of the case 1986 Patent Application No. 198419 2
) Name of the invention Sliding member 3, Relationship with the case of the person making the amendment Patent applicant address 1 Toyota-cho, Toyota City, Aichi Prefecture Name (3)
20) Toyota Motor Corporation 4, Agent Address: Φ104 3rd floor, Kayaba-cho Nagaoka Building, 1-5-19 Shinkawa, Chuo-ku, Tokyo Telephone: 551-41.71 (Method) (Voluntary) Procedural Amendment 1986 September 24th 1, Incident Display 1986 Patent Application No. 198419 2
) Name of the invention Sliding member 3, Relationship to the case of the person making the amendment Patent applicant address 1, Toyota-cho, Toyotafu, Aichi Prefecture Name (3)
20) Toyota Motor Corporation Tsuji 46 Agent Address: 3rd floor, Kayabacho Nagaoka Building, 1-5-19 Shinkawa, Chuo-ku, Tokyo 8104 Telephone: 551-. 41716, Subject of amendment Drawing (Figure 2) 7. Contents of amendment As attached.

Claims (1)

[Scope of Claims] A sliding member comprising a first member and a second member that are in contact with each other and slide relative to each other, the sliding surface portion of the first member relative to at least the second member. is a composite material whose reinforcement is a mixture of silicon nitride whiskers and silicon nitride particles, and whose matrix is a metal selected from the group consisting of aluminum, magnesium, tin, copper, lead, zinc, and alloys containing these as main components. At least a part of the reinforcing material is made of a composite material that is a sea urchin-like reinforcing material, and at least a sliding surface portion of the second member relative to the first member has a hardness Hv (50 g). A sliding member characterized in that it is made of steel that has been nitrided with a grade of 550 or higher. (2) The sliding member according to claim 1, wherein the volume percentage of the mixture is 2% or more. (3) The sliding member according to claim 1 or 2, wherein the overall diameter of the sea urchin-shaped reinforcing material is 220 μm or less. (4) In any of the sliding members according to claims 1 to 3, the ratio between the diameter of the particle aggregate at the center of the sea urchin-shaped reinforcing material and the length of the whiskers projecting radially from this. A sliding member characterized in that the value of is 1/10 to 2.