JPH068474B2 - 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. The member of No. 1 is composed of a composite material composed of an aluminum alloy or a magnesium alloy which is composite-reinforced with alumina-silica fibers, and the second member is composed of a metal plated with silicon carbide particle dispersed iron. It relates to a moving 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 discloses 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.

According to the present invention, a sliding member including a first member and a second member, which are in contact with each other and relatively slide, is provided. 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 has a volume ratio of silicon carbide particles of 5 to 5%.
This is achieved by a sliding member characterized by being composed of a metal plated with 35% of silicon carbide particle dispersed iron.

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%. The sliding surface of one member is configured, and the alumina exposed on the sliding surface is
The silica-based fiber not only reduces the degree of direct contact of the matrix with the second member, but also makes the composite material good by virtue of the above-mentioned recesses having the preferable depth, morphology, and area ratio serving as an oil reservoir. That the reinforced fiber is firmly held by the matrix, and the sliding surface of the second member has a volume ratio of silicon carbide particles set to 5 to 35%. Since it is composed of a metal plated with silicon carbide particle-dispersed iron having excellent sliding properties with respect to the composite material, as is clear from the results of the experimental research conducted by the inventors of the present invention, which will be described later, It is possible to obtain a sliding member that is a combination of two members having excellent wear resistance and seizure resistance.

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 reinforcing fiber is set to, for example, 10
It must be set to a relatively large value, such as -30 μm, and therefore the aggression of the composite material to the mating material increases and the risk of abnormal wear due to the falling of the reinforcing fibers increases, resulting in According to the present invention, the abrasion height of both composite materials increases, whereas the present invention forms the concave portion that works well as the oil reservoir, so that the exposed height of the reinforcing fiber is, for example, 1 μm or less. Therefore, it is possible to reduce the aggression of the mating material and the risk of abnormal wear, which also reduces the wear amount of the two members.

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 volume ratio of the silicon carbide particles contained in the silicon carbide particle-dispersed iron is less than 10%, especially less than 5%, the wear amount of the second member cannot be sufficiently reduced, and conversely If the volume ratio exceeds 30%, especially 35%, the amount of wear of the first member increases. Therefore, in the sliding member of the present invention, the volume percentage of the silicon carbide particles contained in the silicon carbide particle-dispersed iron is set to 5 to 35%, preferably 10 to 30%.

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-off 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,
The average particle diameter of the silicon carbide particles contained in the silicon carbide particle-dispersed iron is less than 0.5 μ, particularly less than 0.3 μ, and further 0.1.
When it is less than μ, the wear resistance and seizure resistance of the composite material cannot be sufficiently improved, and conversely, the average particle diameter of the silicon carbide particles is 2.5 μ, particularly 5 μ, and further 10 μ. When it exceeds, the opponent's aggressiveness of the composite material increases. Therefore, according to one detailed characteristic of the present invention, the average particle diameter of the silicon carbide particles contained in the silicon carbide particle-dispersed iron is 0.1-10.
μ, preferably 0.3 to 5 μ, more preferably 0.5 to
It is set to 2.5μ.

Further, when the thickness of the plating layer of the silicon carbide particle-dispersed iron is too small, the metal of the second member is exposed because the plating layer disappears due to abrasion, and conversely when the thickness of the plating layer is too large. For this reason, silicon carbide particle-dispersed iron is used more than necessary, and the cost of the sliding member becomes high.
Therefore, the thickness of the plating layer of iron with silicon carbide particles dispersed is 40-
It is preferably about 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. If the volume ratio of the alumina-silica fiber is less than 5%, especially 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 in particular, like an aluminum alloy containing silicon,
It is preferably an aluminum alloy or a magnesium alloy which itself has excellent wear resistance. Further, the metal constituting the second member may be any metal as long as it can be plated with iron having silicon carbide 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 / l, 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. The seizure test and wear test performed on the sliding member composed of the metal composite material and the other member composed of the steel plated with the silicon carbide particle-dispersed iron were compared with those of other materials. Description will be made in comparison with the seizure test and wear test performed on the sliding members made of the combination.

First of all, alumina having an average fiber system 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 performs high-pressure casting using the fiber molded body (the temperature of the molten metal is 730 ° C., the pressure applied to the molten metal is 1000 kg / cm.
^{According to 2} ), a composite material was produced 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, the outer diameter is 25.6 mm, the inner diameter is 20.0 mm, and the length is 16
A large number of cylindrical test pieces having a size of mm and having one end surface as the test surface were prepared, and the surface roughness of the test surface of each test piece 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 a cross section of a test piece thus formed in the vicinity of a surface to be tested. In the figure, 1 indicates alumina-silica fiber as a reinforcing fiber, and 2 indicates an aluminum alloy as a matrix. And 3 indicates a recess.

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 of the opening lengths Wi of the recesses 3 to a certain reference length L of an arbitrary cross section of the composite material is 20%. ~ E
Was formed.

Then, these cylindrical test pieces and electrolytic test were not performed, so that the cylindrical test piece B made of the composite material in which the depth of the recesses, the exposed height of the alumina-silica fiber and the area ratio of the recesses were 0 was sequentially applied to the wear tester. Set, made of various steels and having a size of 30 × 30 × 5 mm, and one of its faces (30 × 30 mm) is brought into contact with the test surface of a flat plate test piece, and those test pieces The normal temperature lubricating oil (Castle motor oil SAE30) is supplied to the contact part of, and the pressing load of the cylindrical test piece against the flat plate test piece is 700 from 10 kg while rotating the cylindrical test piece at 1000 rpm.
A seizure test was carried out in which the seizure limit load was measured by increasing the load up 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 also when the counterpart material is steel plated with silicon carbide particle-dispersed iron, when the composite material is not electrolytically etched (combination B), the seizure limit load is relatively low. On the other hand, when the composite material is electrolytically etched and the counterpart material is steel plated with silicon carbide particle-dispersed iron (combination C), it can be seen that the seizure limit load has a high value.

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 silicon carbide particle dispersed iron has excellent seizure resistance. I understand.

Further, for the combinations A to E of the test pieces 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 wear 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 combination C is made of the aluminum alloy reinforced with the alumina-silica fiber and is electrolytically etched. It can be seen that the combination of such a composite material and a metal plated with silicon carbide particle-dispersed iron 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 (JI
Composite material using S standard MC2) as a matrix (melt temperature 690 ° C, pressure force on the melt 800 kg / cm ² ),
Alumina fibers (95 wt% Al ₂ O ₃₎ which are substantially three-dimensionally randomly oriented at a volume ratio of 5%, and the balance is substantially SiO 2.
₂ , a composite material having an average fiber diameter of 3.2μ, an average fiber length of 8 mm) as a reinforcing fiber and an aluminum alloy (JIS standard ADC12) as a matrix, and an alumina which is substantially three-dimensionally randomly oriented at a volume ratio of 5%. Fiber (95wt% Al
₂ O ₃ , the balance substantially SiO ₂ , average fiber diameter 3.2 μ,
Cylindrical test pieces F ₁ and F ₂ , G ₁ and G ₂ having the same dimensions as those in Example 1, respectively, from a composite material having a reinforcing fiber of an average fiber length of 8 mm) and a matrix of a magnesium alloy (JIS standard MC2). , H ₁ and H ₂ are formed,
By electrolytically etching the surface to be tested of each cylindrical test piece, the average value ▲ ▼ of the depth Di of the recess is 2.0 μ, and the average value of the depth Di with respect 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)
A flat plate test piece and a test surface made of silicon chrome steel (JIS standard SWOSC-V) plated with silicon carbide particle-dispersed iron (average particle diameter of silicon carbide particles: 1.5 μ, volume ratio of silicon carbide particles: 10%) A flat plate test piece was prepared, and a seizure test and an abrasion test were carried out with the combinations of test pieces shown in Table 2 below under the same conditions and conditions as in Example 1 described above.

The results of these seizure test and wear test are respectively
It is shown in FIGS. 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 carbide. When plated with particle-dispersed iron, the seizure limit load is high, and the amount of wear of the composite material and the mating material is small, so it can be seen that these combinations have excellent seizure resistance and wear resistance. .

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.
₈ was formed, and for each test piece, under the same conditions and conditions as in Examples 1 and 2, the average particle size of the silicon carbide particles was 1.5 μ, and the volume ratio of the silicon carbide particles was 10%. A seizure test and a wear test were performed using silicon chrome steel (JIS standard SWOSC-V) plated with silicon carbide particle dispersed iron 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%. Moreover, according to FIG. 7, the area ratio of the recesses is 5 to 40%.
It can be seen that the wear amount of the cylindrical test piece and the flat plate test piece becomes a low value in the case of about the degree.

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 What range was appropriate for the volume ratio of the silicon carbide particles of the silicon carbide particle-dispersed iron plated on the surface of the metal constituting the second member was examined.

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 carbide particle-dispersed iron (average particle diameter of silicon carbide particles of 1.5) having various volume ratios of silicon carbide particles.
μ) plated silicon chrome steel (JIS standard S
Seven flat plate test pieces of WOSC-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 volume ratio (%) of silicon carbide particles contained in the silicon carbide particle-dispersed iron.

According to FIG. 8, the wear amount of the cylindrical test piece is a high value in the region where the volume ratio of the silicon carbide particles exceeds 30%, particularly 35%, and the volume ratio of the silicon carbide particles is less than 10%.
Especially in the region of less than 5%, the wear amount of the flat plate test piece is high. Therefore, in order to reduce the wear amount of both the cylindrical test piece and the flat plate test piece, the volume ratio of the silicon carbide particles is 5%.
It can be seen that it is preferably 35%, especially 10-30%.

Example 5 Using the alumina-silica fibers and aluminum alloys used in Example 1 above, reinforced with substantially 3-dimensional randomly oriented alumina-silica fibers with a volume percentage of 7%. A cylinder liner made of an aluminum alloy is manufactured by high pressure casting (the temperature of the molten metal is 730 ° C., the pressure applied to the molten metal is 1000 kg / cm ² ), and the liner is cast by gravity casting to obtain a cylinder bore diameter of 80
5 mm cylinder block for 4-cylinder 4-cycle internal combustion engine
Individually formed. Then, the cylinder bore of one cylinder block was finished to have a surface roughness of 0.6 μRz by honing 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 with 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 cylinder block having an average exposed height of 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 various steel piston rings 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 and the outer peripheral surface of the piston ring of the combination C cylinder block are 20 μ or less and 10 μ or less, respectively, whereas the average wear amounts of the cylinder bore and the outer peripheral surface of the piston ring of the other combination cylinder block are 40 ~
80 [mu], 40-70 [mu], so it was found that the cylinder block and piston of combination C were much more wear resistant than the cylinder blocks and pistons of the other combinations.

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

[Brief description of 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 conducted on combinations of various steels with a composite material having alumina-silica fibers as reinforcing fibers and an aluminum alloy as a matrix, respectively. FIG. 5 and FIG. 5 are graphs showing the results of a seizure test and an abrasion test conducted on various combinations of members, and FIGS. 6 and 7 are each a parameter of the area ratio of recesses on the matrix surface of the composite material. FIG. 8 is a graph showing the results of the seizure test and the abrasion test, and FIG. 8 is a graph showing the results of the abrasion test conducted with the volume ratio of the silicon carbide particles contained in the silicon carbide particle dispersed iron as a parameter. 1 ... Alumina-silica fiber, 2 ... Aluminum alloy, 3
… Recesses, 4… Surface

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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 plated with silicon carbide particle-dispersed iron having a volume ratio of silicon carbide particles of 5 to 35%. A sliding member characterized by being made of metal. 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 carbide particles contained in the silicon carbide particle-dispersed iron have an average particle diameter of 0.1 to 10 μm. Characteristic sliding member. 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.