JPH068475B2 - Sliding member - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member composed of a first member and a second member that abut against each other and slide relative to each other, and more specifically, to the sliding member. Member is composed of a composite material composed of an aluminum alloy or magnesium alloy composite-reinforced with alumina-silica fibers, and the second member is composed of a metal plated with a silicon nitride particle-dispersed Ni-P alloy. Of the sliding member.

2. Description of the Related Art In order to improve the wear resistance and seizure resistance of a fiber-reinforced metal composite material, the applicant of the present application has disclosed in Japanese Patent Application No. 61-61798 filed by the same applicant as the applicant of the present application. A specific surface of a fiber-reinforced metal composite material having an inorganic fiber as a reinforcing fiber and an aluminum alloy or a magnesium alloy as a matrix is formed by electrolytic etching, and a part of the reinforcing fiber is exposed at the specific surface. , Having concave portions on the surface of the matrix between the reinforcing fibers exposed on the specific surface, the average depth of the concave portions is 1.5 μm or more, and the average ratio of the depth to the opening diameter of the concave portions. A fiber-reinforced metal composite material having a value of 0.01 or more was proposed.

Problems to be Solved by the Invention Although the above-mentioned composite material is excellent in wear resistance and seizure resistance, the above-mentioned one member of the sliding member consisting of two members that abut against each other and slide relative to each other. When the above composite material is applied, the amount of wear of one member or the other member may increase depending on the material of the other member.

The inventors of the present application are a sliding member including a first member and a second member that are in contact with each other and relatively slide, and the first member uses alumina-silica fiber as a reinforcing fiber. When the second member is made of a composite material as described above and the second member is made of metal, the first member is made to reduce the amount of wear of these two members and prevent seizure. As a result of various experimental studies on what characteristics are appropriate for the composite material and the metal forming the second member, the area ratio of the recesses of the composite material falls within a certain range. It has been found that it is preferable that the metal that is set inside and that constitutes the second member is plated with a certain specific material.

The present invention is based on the knowledge obtained as a result of various experimental studies conducted by the inventors of the present application, and is a sliding member including a first member and a second member that abut against each other and relatively slide. The first member uses alumina-silica based fibers as reinforcing fibers and aluminum alloy or magnesium alloy as a matrix metal, and the alumina-silica based fibers are exposed on the sliding surface and concave portions are formed on the sliding surface of the matrix. For the purpose of providing a sliding member composed of a fiber-reinforced metal composite material having a second member composed of a plated metal, and having excellent wear resistance and seizure resistance of both members. There is.

Means for Solving the Problems According to the present invention, the above-mentioned object is a sliding member including a second member of a first member that abuts each other and relatively slides. At least the sliding surface portion of one member with respect to the second member is 40 wt% or more Al ₂ O ₃ , and the balance is substantially SiO ₂ with a volume ratio of 3 to 30% alumina-silica fiber as a reinforcing fiber and aluminum. Made of a fiber-reinforced metal composite material having an alloy or magnesium alloy as a matrix, and the sliding surface is electrolytically etched so that a part of the alumina-silica fiber is exposed on the sliding surface and Recesses are formed on the surface of the matrix between the alumina-silica based fibers exposed on the moving surface, and the average depth of the recesses is 1.
5 μ or more, the average value of the ratio of the depth to the opening diameter of the recess is 0.01 or more, and the area ratio of the recess is 5 to 5 μm.
40%, and at least the sliding surface portion of the second member with respect to the first member is made of a metal plated with a silicon nitride particle-dispersed Ni-P alloy, and the P content of the Ni-P alloy is 40%. Is 5 to 15% by weight, and the volume ratio of the silicon nitride particles contained in the Ni-P alloy is 5 to 30%.

EFFECTS AND EFFECTS OF THE INVENTION According to the present invention, there is provided a fiber-reinforced metal composite material comprising alumina-silica fibers having a volume ratio of 3 to 30% as reinforcing fibers and an aluminum alloy or magnesium alloy as a matrix, and the sliding surface thereof. A part of the alumina-silica fiber is exposed to the sliding surface by the electrolytic etching, and a concave portion is formed on the surface of the matrix between the alumina-silica fiber exposed on the sliding surface. Is 1.5 μm or more, the average value of the ratio of the depth to the opening diameter of the recess is 0.01 or more, and the area ratio of the recess is 5 to 40%. One member is constituted, whereby not only the degree of direct contact of the matrix with the second member by the alumina-silica based fibers exposed on the sliding surface is reduced, but also the above-mentioned preferable depth and shape.
And the concave portion of the area ratio works well as an oil reservoir to ensure good oil retaining property of the composite material, and a state in which the reinforcing fibers are firmly held by the matrix, and the second member is made of Ni. -P content of P alloy is 5
A silicon nitride particle-dispersed Ni-P alloy having excellent sliding characteristics with respect to the composite material by setting the volume ratio of the silicon nitride particles contained in the Ni-P alloy to 5 to 30% by setting to 15 wt%. Since it is composed of plated metal, it is composed of a combination of two members that are excellent in wear resistance and seizure resistance, as is clear from the results of the experimental research conducted by the inventors of the present application, which will be described later. A sliding member can be obtained.

Further, in order to sufficiently improve the abrasion resistance of the composite material when the concave portion acting as an oil reservoir is not formed on the surface of the matrix, the exposed height of the alumina-silica fiber is set to, for example, 10 to 30 μm. Since it must be set relatively large, the aggression of the composite material with respect to the mating material increases, and the risk of abnormal wear due to the fall-off of the alumina-silica fibers increases, resulting in the mating material and the composite material. While the amount of wear of both materials is increased, according to the present invention, since the concave portion that works well as an oil reservoir is formed on the surface of the matrix, the exposed height of the alumina-silica-based fiber is set to, for example, 1 μm. It can be reduced to the following, which can reduce the aggression against the mating material and the risk of abnormal wear, which also reduces the wear amount of the two members. Can be reduced.

According to the results of the experimental research conducted by the inventors of the present application, when the area ratio of the recesses, that is, the ratio of the total opening area of the recesses to the total area of any region of the sliding surface of the composite material is less than 5%. Cannot retain a sufficient amount of lubricating oil on the surface of the composite material, and when the area ratio of the recesses exceeds 40%, the amount of lubricating oil retained in the recesses becomes rather small, and the surface of the composite material The strength of the matrix that holds the alumina-silica-based fibers exposed to the surface decreases, so that the alumina-silica-based fibers are likely to fall off and the amount of abrasion of the composite material increases.
Therefore, in the sliding member of the present invention, the area ratio of the recess is 5
It is set to -40%.

According to the results of the experimental research conducted by the inventors of the present application,
When the P content of the silicon nitride particle-dispersed Ni-P alloy is less than 7 wt%, particularly less than 5 wt%, the wear resistance and seizure resistance of the second member cannot be sufficiently improved, and conversely. P
If the content exceeds 13 wt%, especially 15 wt%, the opponent attack of the second member increases, the amount of wear of the composite material increases, and the seizure resistance decreases. Therefore, in the sliding member of the present invention, the P content of the silicon nitride particle-dispersed Ni-P alloy is set to 5 to 15 wt%, preferably 7 to 13 wt%.

According to the results of the experimental research conducted by the inventors of the present application,
When the volume ratio of the silicon nitride particles contained in the silicon nitride particle-dispersed Ni-P alloy is less than 10%, particularly less than 5%, the wear amount of the second member cannot be reduced sufficiently, and conversely nitriding is performed. If the volume ratio of silicon particles exceeds 28%, especially 30%, the amount of wear of the first member increases. Therefore, in the sliding member of the present invention, the volume ratio of the silicon nitride particles contained in the silicon nitride particle-dispersed Ni-P alloy is set to 5 to 30%, preferably 10 to 28%.

According to the results of the experimental research conducted by the inventors of the present application,
If the average value of the exposed height of the alumina-silica fiber on the specific surface of the composite material exceeds 1 μ, the counterpart material is excessively abraded by the alumina-silica fiber exposed from the surface of the composite material. On the contrary, the amount of wear increases, and abnormal wear due to the fall of the alumina-silica fiber is likely to occur. Therefore, according to one detailed feature of the present invention, the average value of the exposed height of the alumina-silica based fibers on the sliding surface of the composite material constituting the first member is set to 1 μm or less.

According to the results of the experimental research conducted by the inventors of the present application,
When the average particle diameter of the silicon nitride particles contained in the silicon nitride particle-dispersed Ni—P alloy is less than 0.5 μ, particularly less than 0.3 μ, and further less than 0.1 μ, the abrasion resistance of the composite material and the The seizure resistance cannot be sufficiently improved, and conversely, when the average particle diameter of the silicon nitride particles exceeds 2.5 μ, particularly 5 μ, and further 10 μ, the opponent attack of the composite material becomes large. Therefore, the average particle diameter of the silicon nitride particles contained in the silicon nitride particle-dispersed Ni-P alloy is set to 0.1 to 10 µ, preferably 0.3 to 5 µ, and more preferably 0.5 to 2.5 µ.

Further, when the thickness of the plating layer of the silicon nitride particle-dispersed Ni-P alloy is too small, the plating layer disappears due to abrasion, and the metal of the second member is exposed. If it is too large, silicon nitride particles dispersed Ni
Since the -P alloy is used more than necessary, the cost of the sliding member becomes high. Therefore, silicon nitride particles dispersed Ni-
The thickness of the P alloy plating layer is preferably about 10 to 150 μm.

In one embodiment of the present invention, the sliding member of the present invention is an internal combustion engine, the first member is a cylinder liner,
The second member is the piston ring.

Alumina as the reinforcing fiber of the composite material of the first member
If the Al ₂ O ₃ content of the silica-based fiber, that is, the fiber containing Al ₂ O ₃ and SiO ₂ as the main components is less than 40 wt%, the abrasion resistance of the composite material cannot be sufficiently improved. Therefore, in the present invention, the Al ₂ O ₃ content is 40 wt.
% Or more of alumina-silica fiber is used. This alumina-silica-based fiber may be either a long fiber or a short fiber, and the average fiber diameter is 100 µ or less, particularly 1 to 40 µ.
It is preferably about the same. When the volume ratio of the alumina-silica fiber is less than 5%, particularly less than 3%, the abrasion resistance of the composite material cannot be sufficiently improved, and conversely the volume ratio of the alumina-silica fiber is small. Is 15%, especially 30
When it exceeds%, the wear amount of the composite material increases. Therefore, the volume ratio of the alumina-silica fiber is set to 3 to 30%, preferably 5 to 15%. Further, the orientation of the alumina-silica-based fiber may be any orientation such as unidirectional orientation, two-dimensional random orientation, and three-dimensional random orientation, but especially in the case of unidirectional orientation and two-dimensional random orientation, the sliding surface is It is preferable that the unidirectional orientation or the two-dimensional random orientation plane is set to be as perpendicular or as close to the angle as possible.

Further, the aluminum alloy and the magnesium alloy may be of any composition as long as they can be electrolytically etched, but particularly aluminum alloys and magnesium alloys having excellent wear resistance themselves, such as aluminum alloys containing silicon. Is preferred. Further, the metal forming the second member may be any metal as long as it is a metal that can be plated with a Ni-P alloy having silicon nitride particles dispersed therein.

Further, the electrolytic solution for electrolytic etching in the present invention may be an aqueous nitric acid solution or an aqueous sodium chloride solution, and when an aqueous nitric acid solution is used, its concentration, potential difference and energization amount are 80 to 160 ml / l and 4.5, respectively. ~ 6.0V, 200 ~
It is preferably set to 450 coulomb / dm ^2, and when an aqueous solution of sodium chloride is used, its concentration, potential difference, and energization amount are 80 to 160 g /, 3.0 to 4.0.
V, preferably set to 100 to 400 coulomb / dm ² .

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

Example 1 A sliding member composed of two members that abut each other and slide relatively to each other, one member of which is electrolytically-etched fiber reinforced with alumina-silica fibers as reinforcing fibers and aluminum alloy as a matrix. It is composed of a metal composite material, and the other member is silicon nitride particle dispersed N
The seizure test and wear test performed on a sliding member made of steel plated with an i-P alloy, and the seizure test and wear test performed on a sliding member made of a combination of other materials. This will be explained in comparison with.

First, alumina with an average fiber diameter of 2.8 μ and an average fiber length of 6 mm
Silica fiber (55 wt% Al ₂ O ₃ , balance SiO)
₂ ) forms a fiber molded body that is substantially three-dimensionally randomly oriented, and high-pressure casting performed using the fiber molded body (the temperature of the molten metal is 730 ° C., the pressure applied to the molten metal is 500 kg / cm ²
Thus, a composite material was prepared in which alumina-silica fibers having a volume ratio of 8% were used as reinforcing fibers and an aluminum alloy (JIS standard ADC12) was used as a matrix. Next, from this composite material, a large number of cylindrical test pieces having an outer diameter of 25.6 mm, an inner diameter of 20.0 mm and a length of 16 mm and having one end surface as a test surface were prepared, and the surface of the test surface of each test piece was prepared. The roughness was finished to 0.6 μRz by grinding.

Then, a concave portion was formed on the surface of the matrix to be tested by electrolytic etching using an aqueous nitric acid solution. FIG. 1 is a schematic view showing an end face in the vicinity of a surface to be tested of a test piece thus formed, showing alumina-silica fiber as a reinforcing fiber, and 2 is an aluminum alloy as a matrix. 3 shows a concave portion.

In this case, by appropriately setting the electrolytic etching conditions, the average value ▲ ▼ of the depth Di of the recessed portion 3 appearing in an arbitrary cross section of the surface to be tested is 2.0 μ, and the depth of the recessed portion 3 with respect to the opening diameter is The average value of the ratios, that is, the depth Di with respect to the opening length Wi of the concave portion 3 appearing in an arbitrary cross section of the surface to be tested.
Average value of the ratio of Is 0.02, and alumina from the surface 4 of the composite material
The average value of exposed height Hi of silica fiber is 0.5μ
And the area ratio of the recesses, that is, the ratio of the total ratio of the opening length Wi of the recesses 3 to a certain reference length L in an arbitrary cross section of the composite material is 20%. ~ E
Was formed.

Then, these cylindrical test pieces and the cylindrical test piece B, which is not subjected to electrolytic etching, and is therefore made of a composite material in which the depth of the recesses, the exposed height of the alumina-silica fiber and the area ratio of the recesses are 0, are sequentially applied to the friction wear tester. The test piece is made of various steels and has a size of 30 × 30 × 5 mm, and one surface (30 × 30 mm) of the steel is contacted with the surface of the flat test piece to be tested. Lubricating oil at normal temperature (castle motor oil SAE30) was supplied to the contact part of the piece, and the pressing load of the cylindrical test piece against the flat plate test piece was 700 from 10 kg while rotating the cylindrical test piece at a rotation speed of 1000 rpm.
A seizure test was conducted in which the seizure limit load was measured by increasing to Kg. The combinations of the cylindrical test piece and the flat plate test piece in this seizure test are as shown in Table 1 below.

The results of the seizure test described above are shown in FIG. From FIG. 2, the seizure limit load can be obtained in any case where the mating material is not surface-treated steel (combination A), gas-nitrided steel (combination D), or chrome-plated steel (combination E). Is a low value and the counterpart material is steel plated with a silicon nitride particle-dispersed Ni-P alloy, the seizure limit load is relatively high when the composite material is not electrolytically etched (combination B). The seizure limit load is high when the composite material is electrolytically etched and the counterpart material is steel plated with a silicon nitride particle-dispersed Ni-P alloy (combination C), whereas the seizure limit load is high. I understand.

From the result of this seizure test, the combination of the electrolytically-etched composite material made of an aluminum alloy reinforced with alumina-silica fiber and the metal plated with the silicon nitride particle-dispersed Ni-P alloy shows seizure resistance. It turns out that it is excellent.

With respect to the test piece combinations A to E shown in Table 1 above, a load was set to 200 kg (constant) and an abrasion test similar to the above-mentioned seizure test was conducted for 1 hour. The results of this abrasion test are shown in FIG. In FIG. 3, the upper half and the lower half represent the wear amount (wear loss mg) of the cylindrical test piece and the flat plate test piece, respectively.

From FIG. 3, the wear amount of the combination C is smaller than that of the other combinations in both the cylindrical test piece and the flat plate test piece, and therefore, the electrolytic etching of the aluminum alloy reinforced with the alumina-silica fiber is performed. It can be seen that the combination of the composite material and the metal plated with the silicon nitride particle-dispersed Ni-P alloy also has excellent wear resistance.

Example 2 In the same manner as in Example 1 above, alumina-silica fibers (alumina used in Example 1) oriented substantially three-dimensionally at a volume ratio of 8% were used. Magnesium alloy (J
Composite material with IS standard MC2 as matrix (melt temperature 700 ℃, pressurizing force 800kg / c)
m ² ), alumina fibers (95 wt% Al ₂ O ₃ , the balance substantially SiO ₂ , average fiber diameter 3.2 μ, average fiber length 8 mm) that are substantially three-dimensionally randomly oriented at a volume ratio of 5%. Reinforcement fiber, aluminum alloy (JIS standard ADC1
2) matrix-based composite material, alumina fibers (95%) that are substantially three-dimensionally randomly oriented at a volume ratio of 5%.
wt% Al ₂ O ₃ , balance substantially SiO ₂ , average fiber diameter 3.2 μ, average fiber length 8 mm) as a reinforcing fiber, and a magnesium alloy (JIS standard MC2) as a matrix. Cylindrical test pieces F ₁ and F ₂ , G ₁ and G ₂ , H ₁ and H ₂ having the same dimensions as those in the case were formed, and the surface to be tested of each cylindrical test piece was electrolytically etched to obtain the depth Di of the concave portion. Average value ▲ ▼ is 2.0μ
And the average value of the ratio of the depth Di to the opening length Wi of the recess Is 0.02, and the average value of the exposed height Hi of the reinforcing fibers is ▲
▼ was 0.5μ, and the area ratio of the recesses was 20%.

Next, silicon chrome steel (JIS standard SWOSC-V)
The flat plate test piece and the test surface are made of silicon nitride particles dispersed N
A flat plate test piece made of silicon chrome steel (JIS standard SWOSC-V) plated with an i-P alloy (average particle size of silicon nitride particles 0.8 μ, volume ratio of silicon nitride particles 10%) was prepared. A seizure test and an abrasion test were conducted on the combinations of test pieces shown in Table 2 under the same procedure and conditions as in the case of Example 1 described above.

The results of these seizure test and abrasion test are shown in FIGS. 4 and 5, respectively. In FIG. 5, the upper half and the lower half represent the wear amount (wear loss mg) of the cylindrical test piece and the flat plate test piece, respectively.

From FIGS. 4 and 5, when the reinforcing fibers are alumina-silica fibers and the matrix is a magnesium alloy,
In either case where the reinforcing fiber is an alumina fiber and the matrix is an aluminum alloy, or in the case where the reinforcing fiber is an alumina fiber and the matrix is a magnesium alloy, the surface of the composite material is electrolytically etched and the counterpart material is silicon nitride. When plated with a particle-dispersed Ni-P alloy, the seizure limit load is high, and the amount of wear of the composite material and the mating material is small. Therefore, these combinations have excellent seizure resistance and wear resistance. I understand.

Example 3 The range of the area ratio of the recesses formed by electrolytic etching was examined appropriately.

Cylindrical test pieces I _{1 to} I as shown in Table 3 below were obtained by electrolytically etching the surfaces to be tested of the 6 cylindrical test pieces prepared in Example 1 under various conditions.
₆ was formed, and the average particle diameter of the silicon nitride particles was 0.8 μ and the volume ratio of the silicon nitride particles was 10% under the same conditions and conditions as in Examples 1 and 2 for each test piece. A seizure test and a wear test were conducted using a silicon chrome steel (JIS standard SWOSC-V) plated with a silicon nitride particle-dispersed Ni-P alloy as a counterpart material.

The results of these tests are shown in FIGS. 6 and 7, respectively. In FIG. 7, the upper half and the lower half show the wear amount (wear loss mg) of the cylindrical test piece and the flat plate test piece, respectively.

From FIG. 6, it can be seen that the seizure limit load becomes high and the seizure hardly occurs when the area ratio of the recesses is about 5 to 40%. Further, from FIG. 7, it can be seen that the wear amount of the cylindrical test piece and the flat plate test piece has a low value when the area ratio of the concave portions is about 5 to 40%.

From the results of these seizure test and abrasion test, it is understood that the area ratio of the recesses is preferably 5 to 40%.

Example 4 Ni-plated on the surface of the metal constituting the second member
The range of the P content of the P alloy is considered to be appropriate.

First, the cylindrical test piece A of Example 1 was formed by high pressure casting and electrolytic etching under the same conditions and conditions as in Example 1 above.
Seven cylindrical test pieces identical to CE were formed. Also, a silicon chrome steel plated with a silicon nitride-dispersed Ni-P alloy (average particle size of silicon nitride particles: 0.8 µ, volume ratio of silicon nitride particles: 10%) having various P contents (JI
Seven flat plate test pieces made of S standard SWOSC-V) were formed.

Then, the cylindrical test piece and the flat plate test piece were combined and a wear test was conducted under the same conditions and conditions as in the case of Example 1 described above. The results of this wear test are shown in FIG. The eighth
In the figure, the horizontal axis represents the P content (wt%) of the Ni-P alloy.

From FIG. 8, the wear amount of the cylindrical test piece is relatively high in the region where the P content exceeds 13 wt%, particularly 15 wt%, and the P content is less than 7 wt%, particularly less than 5 wt%. 1
In the region of more than 3 wt%, especially 15 wt%, the wear amount of the flat plate test piece is relatively high. Therefore, in order to reduce the wear amount of both the cylindrical test piece and the flat plate test piece, the P content should be reduced. It is understood that is preferably 5 to 15 wt%, particularly 7 to 13 wt%.

Example 5 A study was made as to what range is appropriate for the volume ratio of the silicon nitride particles of the silicon nitride particle-dispersed Ni-P alloy to be plated on the surface of the metal constituting the second member.

First, seven cylindrical test pieces having the same specifications as the cylindrical test pieces A and C to E shown in Table 1 were formed by high-pressure casting and electrolytic etching under the same conditions and conditions as in the above-mentioned Example 1. . Further, silicon chrome steel plated with a silicon nitride particle-dispersed Ni-P alloy (average particle diameter of silicon nitride particles: 0.8 μ, P content: 8 wt%) having various volume ratios of silicon nitride particles (JIS standard) SWOSC-V) 7
Individual flat plate specimens were formed.

Then, the cylindrical test piece and the flat plate test piece were combined and a wear test was conducted under the same conditions and conditions as in the case of Example 1 described above. The results of this wear test are shown in FIG. The ninth
In the figure, the horizontal axis represents the volume ratio (%) of the silicon nitride particles contained in the silicon nitride particle-dispersed Ni-P alloy.

From FIG. 9, the volume ratio of silicon nitride particles is 28%, especially 3%.
The wear amount of the cylindrical test piece is high in the area exceeding 0%, and the wear amount of the flat plate test piece is in the area where the volume ratio of the silicon nitride particles is less than 10%, particularly less than 5%. In order to reduce the wear amount of both the cylindrical test piece and the flat plate test space, the volume ratio of the silicon nitride particles should be 5 to 5.
It is understood that 30%, particularly 10 to 28% is preferable.

Example 6 Using the alumina-silica fibers and aluminum alloys used in Example 1 above, reinforced with 10% by volume alumina-silica fibers oriented in a substantially three-dimensional random manner. A cylinder liner made of an aluminum alloy is manufactured by high pressure casting (melt temperature 730 ° C., pressure applied to the melt 500 kg / cm ² ), and the liner is cast by gravity casting to form a cylinder bore diameter of 80
mm 4 cylinder 4 siul 5 cylinder block for internal combustion engine
Individually formed. Next, the cylinder bore of one cylinder block was finished by boning to a surface roughness of 0.6 μRz to form a cylinder block (exposed height of reinforcing fiber: 0 μ, area ratio of recess: 0%). Further, after the cylinder bores of the other remaining cylinder blocks are finished to have a surface roughness of 0.6 μRz by honing, the average depth of the recesses is 1.9 by electrolytic etching using a nitric acid aqueous solution.
μ, average value of the ratio of the depth to the opening diameter of the recess is 0.01
8. A silida block having an average exposed height of the reinforcing fibers of 0.3 μ and an area ratio of recesses of 6% was formed.

Then, the internal combustion engine incorporating these cylinder blocks and piston rings made of various steels corresponding to the combinations A to E of Example 1 was subjected to a high-speed durability test at 6000 rpm for 200 hours. Scuffing was found to occur in the cylinder bores of the cylinder blocks B, D, and E, whereas no scuffing was found in the cylinder bores of the cylinder blocks of combination C. The average wear amounts of the cylinder bore of the combination C cylinder block and the outer peripheral surface of the piston ring are 20 μ or less and 5.0 μ or less, respectively, whereas the average wear amount of the cylinder bore and the outer peripheral surface of the piston ring of the other combination cylinder block is less than 5.0 μ. The amount is 40 ~
It was found to be 80 [mu], 20-50 [mu], and therefore the cylinder block and piston of combination C were much more wear resistant than the cylinder blocks and pistons of the other combinations.

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

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a cross section of a surface portion of a fiber-reinforced metal composite material constituting a first member of a sliding member according to the present invention,
2 and 3 are graphs showing the results of a seizure test and an abrasion test performed on combinations of various steels with a composite material having alumina-silica fibers as reinforcing fibers and aluminum alloy as a matrix, respectively. FIG. 5 and FIG. 5 are graphs showing the results of a seizure test and an abrasion test performed on various combinations of members. FIG. 8 is a graph showing the results of the seizure test and wear test performed, and FIG. 8 is a silicon nitride particle-dispersed Ni-P.
FIG. 9 is a graph showing the results of a wear test conducted with the P content of the alloy as a parameter, and FIG.
It is a graph which shows the result of the abrasion test performed using the volume ratio of the silicon nitride particles contained in P alloy as a parameter. 1 ... Alumina-silica fiber, 2 ... Aluminum alloy, 3
… Recesses, 4… Surface

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F02F 1/00 D 8503-3G

Claims (4)

[Claims] 1. A sliding member comprising a first member and a second member which are in contact with each other and slide relatively to each other, wherein at least a sliding surface portion of the first member with respect to the second member is provided. 40% by weight or more of Al ₂ O ₃ , the balance being a SiO ₂ -silica-based fiber having a composition of substantially SiO ₂ and a volume ratio of 3 to 30%, and a fiber-reinforced metal composite material using aluminum alloy or magnesium alloy as a matrix A part of the alumina-silica based fiber is exposed to the sliding surface by electrolytically etching the sliding surface, and the alumina between the alumina-silica based fibers is exposed to the sliding surface. Concave portions are formed on the surface of the matrix, the average depth of the concave portions is 1.5 μm or more, and the average ratio of the depth to the opening diameter of the concave portions is 0.01 or more, The area ratio is 5 to 40%, and at least the sliding surface portion of the second member with respect to the first member is made of a metal plated with a silicon nitride particle-dispersed Ni-P alloy. The P content of the alloy is 5-15
%, and the volume ratio of the silicon nitride particles contained in the Ni-P alloy is 5 to 30%. 2. The sliding member according to claim 1, wherein the average exposed height of the alumina-silica fibers on the sliding surface is 1 μm or less. Sliding member. 3. The sliding member according to claim 1 or 2, wherein the silicon nitride particle-dispersed Ni-P is used.
The average particle size of the silicon nitride particles contained in the alloy is 0.1 to 1
A sliding member characterized by being 0 μ. 4. The sliding member according to any one of claims 1 to 3, wherein the first member is a cylinder liner for an internal combustion engine, and the second member is a piston ring. A sliding member characterized by being present.