JPS63426A - Sliding member - Google Patents

Abstract

PURPOSE:To improve the wear resistance, seizure resistance, etc., of a sliding member by forming a 1st member of a specific composite fiber-reinforced metal lic material and a 2nd member of a metal coated with a thermally sprayed layer of Mo. CONSTITUTION:The part of the sliding member from a piston head 10 along the lateral outside peripheral face 2 of a piston 1 as the 1st member down to the part below the bottom surface of a top ring groove 6 is formed of the following composite material 12: The material 12 consisting of alumina.silica fibers composed of >=40wt% Al2O3 and the balance substantially SiO2 and having 3-30% vol. ratio as reinforcing fibers and an Al alloy or Mg alloy as matrix is used. On the other hand, the top ring 4 as the 2nd member sliding relatively with the above-mentioned piston 1 in contact therewith is formed of a metal such as spheroidal graphite cast iron coated with the thermally sprayed layer of Mo (not shown) on the bottom surface 17 of the top ring 4 which is the sliding surface part thereof with the piston 1.

Description

[Detailed Description of the Invention] Field of Application of B-Rakudo The present invention relates to a sliding member consisting of a first member and a second member that are in contact with each other and slide relative to each other. One member is made of a composite material made of aluminum alloy or magnesium alloy reinforced with alumina-silicon yarn fibers, and the second member is made of metal coated with a thermally sprayed layer of livdenum. This relates to sliding members.

2. Description of the Related Art In a sliding member consisting of two members that come into contact with each other and slide relative to each other, the amount of wear of one or both of those members may be large depending on the combination of the two members.
May cause premature end of life. In order to deal with this problem, for example, Japanese Patent Application Laid-Open No. 58-93838 and Japanese Patent Application Laid-Open No. 58-93839 filed by the same applicant as the applicant of the present application disclose alumina using an aluminum alloy or a magnesium alloy as a matrix. One member is made of a fiber-reinforced metal composite material with inorganic [ff] as the reinforcing fiber, such as silica fiber, and the other member is made of steel of a predetermined hardness. Attempts are being made to improve the properties.

Problems to be Solved by the Invention However, in the case where I and the moving member are made up of two members that come into contact with the bean and slide relative to each other, one of the members is made of a fiber-reinforced metal composite material. Depending on the texture of the other member, wear of the other member may increase, and problems such as burnout may occur between these members.

Prior to the present invention, in a sliding member consisting of a first member and a second member that were in contact with each other and slid relative to each other, the first member was made of alumina-silica-based navy blue with reinforcing fibers. When the second member is made of a composite material and the second member is made of a metal, various experimental studies have been conducted to find out what characteristics the metal that makes up the second part l should have. As a result of research, it was found that iv! l! It has been found that it is preferable that it be overturned.

The present invention is based on the knowledge obtained as a result of various experimental studies conducted by the present invention, and provides 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 first member is made of a fiber-reinforced metal composite material reinforced with alumina-silica 111F and has an aluminum alloy or magnesium alloy as a matrix, and the second member is made of a sprayed layer of a specific metal. The Fi! The purpose is to provide members for first-time use of ff.

Means for Solving the Problems According to the present invention, the above-mentioned object is achieved by providing a sliding member comprising a first member and a second member that are in contact with each other and slide relative to each other, At least the sliding surface portion of the first member relative to the second member has a content of 40 wt% or more A I 203
, jN portion is composed of a 41 ift reinforced metal composite material with a volume fraction of 3 to 30% alumina-silica fibers having a composition substantially equal to 2 S i 02 ' as reinforcing fibers and an aluminum alloy or magnesium alloy as a matrix, The active surface of the second member relative to at least the first member is achieved by a sliding member made of metal coated with a sprayed layer of molybdenum.

According to the present invention, the active surface portion of the first member for at least the second member is an alumina-silinoco based material with a volume fraction of 3 to 30% [ff is reinforcing fiber and aluminum alloy or magnesium alloy] The matrix is made of a fiber-reinforced metal composite material (M), and the sliding surface of the second member with respect to at least the first member has excellent sliding characteristics.
As is clear from the results of experimental research conducted by the inventors, which will be explained later, the wear resistance and seizure resistance of the two members is 1cIII. A member for #J can be obtained.

According to the results of experimental research conducted by the inventor of the present application, when the sliding surface of the second member is made of metal coated with a sprayed layer of molybdenum, the surface roughness of the sprayed layer Even if the second part H is relatively large, the second part
The amount of wear of the second member can be reduced, and the amount of wear of the two members can be suppressed to a small value especially when the surface roughness of the 01 layer is 1.2 μRz or less. Therefore, according to another detailed feature of the invention, the surface roughness of the sprayed layer is set to 1.2 μRz or less.

Also, according to the results of experimental research conducted by the inventor of the present application, the first ? X! When the M moving surface (in January) was electrolytically etched, a part of the realumina silica-based 11 material was exposed on the rotating surface, and on the surface of the matrix between the alumina and silica fibers exposed on the moving surface. When a recess is formed, the wear resistance and seizure resistance of the first and second members can be further improved. Therefore, according to yet another detailed feature of the present invention, the sliding surface of the first member is electrolytically etched so that a part of the alumina-silica fiber is exposed on the sliding surface, Alumina exposed on P moving surface
It is used in a state where four parts are formed on the surface of the matrix between silica-based INs.

Also, if the thickness of the molybdenum spray layer is too small,
Due to wear, the sprayed layer disappears and the metal of the second member is exposed. Conversely, if the thickness of the sprayed layer is too large, the time required for spraying becomes longer and more molybdenum is used than necessary. Therefore, the cost of the sliding member becomes high. Therefore, the thickness of the molybdenum sprayed layer is preferably 5 microns or more, particularly 5 to 200 microns, and more preferably 10 to 150 microns.

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

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

Furthermore, alumina as a reinforcing fiber of the composite material of the second member.
When the Al t, 03-containing HB of the silica-based fibers, ie, the fibers mainly composed of AI 203 and 5102, is less than 40 wt %, the wear resistance of the composite material cannot be sufficiently improved. Therefore, in the present invention, an alumina-silica fiber having an Al 203 content of 40 wt % or more is used. The aluminum-silica fibers may be either navy blue fibers or staple fibers, and preferably have an average MA diameter of 100 μm or less, particularly about 1 to 40 μm.

Furthermore, if the volume fraction of alumina-silica IIM is less than 5%, especially less than 3%, the abrasion resistance of the composite material cannot be sufficiently improved; When the volume fraction exceeds 15%, especially 30%, the amount of wear of the composite material and the second member increases. Therefore alumina
The volume fraction of the silica-based TUG-FF is set to 3 to 30%, preferably 5 to 15%. Furthermore, the orientation of the alumina-silica fibers may be any orientation such as unidirectional orientation, two-dimensional random orientation, three-dimensional random orientation, etc., but especially in the case of unidirectional orientation and two-dimensional random orientation, the sliding surface It is preferable to set the angle as perpendicular to or as close to this as possible with respect to the unidirectional orientation or the two-dimensional random orientation V-plane.

Further, the metal constituting the second member may be any metal as long as it can be thermally sprayed with molybdenum.

Furthermore, the method for melting molybdenum may be any arbitrary method such as gas spraying, arc spraying, or plasma spraying.

Embodiments of the tree 51 will be described in detail below with reference to the accompanying drawings.

Example 1 P consisting of two members that are in contact with each other and layered relative to each other
I! One of the members for the official part is made of a fiber-reinforced metal composite material with an alumina-silica fiber-reinforced strip and an aluminum alloy matrix, and the other member is made of molybdenum. In the sprayed layer? l! ! Compare the wear and seizure tests conducted on sliding members made of covered metal with the wear and seizure tests conducted on sliding members made of other combinations of materials. explain.

First, a fiber molded body is formed in which alumina-silica fibers (55wt% Al 203 , the remainder substantially Si 02 ) having an average Ift diameter of 2.8μ and an average fiber length of 6I are oriented in a three-dimensional random manner. Alumina with a volume fraction of 8% is produced by high-pressure casting (molten metal temperature 730°C, pressure applied to the molten metal 500 kl'cm2) using a fiber molded body.
A composite material was produced in which silica fibers were reinforced and aluminum alloy (JIS standard ΔC8Δ) was used as a matrix. Next, the size of this composite material is 16X6X10mm.
A large number of qr + anti-test specimens were prepared with one surface (16 x 6 ml) as the test surface. For comparison purposes, a large number of flat test specimens were prepared that were made of aluminum alloy (JIS standard ΔC8A) that was not reinforced with alumina-silica [11] and had the same dimensions as the flat test specimens described above.

Next, these flat test pieces were sequentially set in a 1'J'IA abrasion tester, and the mating parts, which were spheroidal graphite cast iron <JIS
lA rating "CD70), molybdenum or cast iron (0.8wt
%C10,3wt%S; ,O,01wt%P1 remainder F
e) Spheroidal graphite U iron (J
■Contact with the end face of a cylindrical test piece made of S standard FCD70), and while supplying 1 juice 1 oil (Kiki I Tension Motor A-Ile 5W-30) at a temperature of 150°C to the contact part of the test piece, load A wear test was conducted in which a cylinder was rotated for 1 hour at a rotation speed of 160 rpm.

The combination V of the flat plate test piece and the cylindrical test piece is as shown in Table 7 below.
Melting! For layer 8, after cleaning one end surface of the cylindrical test piece by shot blasting, perform plasma spraying using a plasma spraying device manufactured by METCO (<3MB) under the conditions shown in Table 2 below. was formed by. Also, in Table 1, union t! Melting of cylindrical test pieces from At to A5 (g)
The unit of surface roughness of the layer is μRz, and the surface roughness of the test surface of the cylindrical test pieces of other combinations is all 1.2 μRz, and the surface roughness can be changed by changing the grinding conditions for the test surface. Adjusted l[.

Table 1 (Part 1) Table 1 (Part 2) )i: 1) Sprayed layer thickness 150μ, hardness T+V8
002)? OA layer thickness 150μ, hardness LLv500
Table 2 (Plasma spraying conditions) Ar gas flow rate: 2300Q/hr Hp 'jj' Suspension: 450Q/hr supply ti
Flow = 450-500A Average particle size of sprayed powder: 20μ Supply height of sprayed powder: 40g/n+in Spraying distance:
100111 The results of this wear test are shown in FIG. In addition, in Figure 1,
The upper half represents the wear amount (wear scar depth μ) of the flat plate test piece, and the lower half represents the wear amount (wear distance mma>) of the cylindrical test piece, which is the mating material (see Fig. 2 for illustration). ~The same applies to Figure 4).

From Figure 1, wear of the deck test piece of combination Aa=A+o■
is a very high value, and it can be seen that especially in the case of the combination L' A 10, the Iq4 wear of the cylindrical test piece is also a relatively high value. Furthermore, the wear distance of the flat plate test pieces of combinations A1 to A7 is much smaller than that of the flat plate test pieces of combinations 88 to A+o, but among these, combination t! 'A
The wear amount of the cylindrical test pieces of e and A7 is the combination 88 and As.
It can be seen that the wear amount of the cylindrical test piece of combination A+-As is smaller than that of combinations A6 and A7. Thus, in the case of combinations △1 to A5 of a flat plate test piece made of an aluminum alloy reinforced with alumina-silica fibers and a cylindrical test piece made of spheroidal graphite cast iron coated with a molten molybdenum OA layer, a flat plate test is performed. The amount of wear of both the piece and the cylindrical test piece is smaller than that of other combinations, and the surface roughness of the sprayed layer is preferably 1.2 μRz or less, especially from the results of the wear tests for combinations A1 to A5. I understand.

In addition, combinations A1 to Δ1o of test pieces shown in Table 1
For the cylindrical test on the flat plate test piece, lubricating oil (castle motor oil 5W-30) at room temperature was supplied to the contact area between the flat plate test piece and the cylindrical test piece, and the cylindrical test piece was rotated at a rotation speed of 1000 ram. Pressure load of piece is 10ku
The load was increased to 700 ko, and a seizure test was conducted to measure the maximum seizure load.

As a result of this test, combinations A+ to A5, especially combinations A3 to
The seizure limit load of A5 is higher than any other combination,
Therefore, it was confirmed that these combinations also have excellent seizure resistance.

In the same manner as in Example 1 above, alumina-silica mM (alumina-silica fibers used in Example 1) which was substantially three-dimensionally randomly oriented at a volume fraction of 8% was prepared. ) is used as the reinforcing fiber, magnesium alloy (JI
High-pressure casting of a composite material with S standard F8MC2) as a matrix <I lagoon temperature 700℃, pressure applied to the melt field 800℃
kg/cm2), and a large number of flat test pieces having the same dimensions as in Example 1 were prepared from the composite material.

Next, a wear test and a seizure test were conducted on these flat test pieces using the combinations of test pieces shown in Table 3 below under the same number of test pieces and under the same conditions as in Example 1. In addition, the molten molybdenum tA layer was formed on the cylindrical test pieces of combinations 81 to B4 shown in Table 3 below in the same manner and under the same conditions as the combinations A+ - A3 and A5 shown in Table 1. Surface roughness is 1! The surface roughness of the surface to be tested of the cylindrical test piece of combination B6 was 1.2 μR2.

Table 3 The results of this wear test are shown in Figure 2. From FIG. 2, compared to the case of combination B5, the wear amount of combinations B+ to B4 is lower l+11 for both the flat plate test piece and the cylindrical test piece, and especially the wear amount of combinations B3 and B4 is lower than that of the flat plate test piece Both of the cylindrical specimens have a lower straightness than the combinations B+ and B2, and are therefore made of spheroidal graphite cast iron coated with a composite material made of a magnesium alloy reinforced with alumina-silica fibers and a sprayed layer of molybdenum. It can be seen that the combination with the above shows excellent wear resistance, and the surface roughness of the molybdenum sprayed layer is preferably 1.2 μRz or less.

Also, although not shown in the figure, as a result of the seizure test, the combination of a composite material made of a magnesium alloy reinforced with aluminum thick silica fibers and spheroidal graphite cast iron coated with a sprayed layer of molybdenum was confirmed. It was also confirmed that it has excellent seizure resistance.

Example 3 In the same manner as in Example 1 above, alumina fibers (95 wt% A+203, the remainder substantially Si 02 ,
Average 1AIIIlt diameter 3.2μ, average line N length 8mm) is reinforced 111, aluminum alloy LJIS standard ADC
High-pressure casting of a composite material with a matrix of
A large number of the same judicial flat test pieces as in Example 1 were prepared from the composite material.

Next, these flat test pieces were subjected to wear tests and seizure tests using the test piece combinations shown in Table 4 below in the same manner and under the same conditions as in Example 1. The cylindrical test pieces of combinations CI to C4 shown in Table 4 below were each coated with a molybdenum sprayed layer in the same manner and under the same conditions as combinations A1-A3 and A5 shown in Table 1. The surface roughness was adjusted, and the surface roughness of the surface to be tested of the cylindrical test piece of combination tjc5 was 1.2 μRz.

Table 4 The results of this wear test are shown in Figure 3. From Fig. 3, the wear amount of combinations c1 to c4 is lower than that of combination C5 for both the flat plate test piece and the circular Both the flat plate test piece and the cylindrical test piece have lower values than the combinations 0 weight and C2, and therefore the spherical shape coated with a composite material made of aluminum alloy reinforced with alumina fibers and a sprayed layer of molybdenum. The combination with Black 11 cast iron has excellent wear resistance, and the surface roughness of the molybdenum sprayed layer is 1.
．． It can be seen that it is preferable that it is 2 μRz or less.

Also, although not shown in the figure, as a result of the seizure test, the combination of a composite material made of aluminum alloy reinforced with alumina fibers and spheroidal graphite cast iron coated with a sprayed layer of molybdenum has good seizure resistance. was also confirmed to be excellent.

Actually! @4 Alumina It was oriented in a substantially three-dimensional random manner at a volume fraction of 8% in the same manner as in Example 1 above.
s (same as the alumina fiber used in Example 3) was used as the reinforcing fiber, and magnesium alloy (JIS standard MO2>
A composite material with a matrix of
A large number of flat test pieces having the same dimensions as in Example 1 were prepared from the composite material.

Next, a wear test and a seizure test were conducted on these flat test pieces in the same manner and under the same conditions as in Example 1 using the combinations of test pieces shown in Table 5 below. The cylindrical test pieces of combinations D+ to D4 shown in Table 5 below were coated with a molybdenum sprayed layer in the same manner and under the same conditions as combinations A1-A3 and As shown in Table 1 below. The roughness was adjusted, and the surface roughness of the test surface of the cylindrical test piece of combination D5 was 1.2 μRz.

Table 5 The results of this wear test are shown in Figure 4. From FIG. 4, compared to the case of combination D5, the wear amount of combinations D+ to D4 is a lower value for both the flat plate test piece and the cylindrical test piece.
In particular, the wear amount of combinations D3 and D4 is lower than that of combinations D1 and D2 for both flat plate and cylindrical test pieces, and therefore, the composite material made of a magnesium alloy reinforced with alumino fibers and the thermal spraying of molybdenum The combination with spheroidal graphite cast iron coated with a layer also provides excellent wear resistance, and the surface roughness of the molybdenum sprayed layer is 1.2μR.
It can be seen that it is preferable that z or less.

Also, although not shown in the figure, as a result of a seizure test, the combination of a composite material made of a magnesium alloy reinforced with alumina fibers and spheroidal graphite cast iron coated with a sprayed layer of molybdenum is highly resistant to seizure. It was confirmed that he was able to return home.

Example 5 Alumina-silica fibers identical to the alumina-silica fibers used in Example 1 were oriented in a substantially three-dimensional random manner to form an m-fiber molded body, and the wire-pyramid molded body was used. Through high-pressure casting (molten N 730°C, 28 m2-t6 pressing force 500 kg/C12), an aluminum alloy (JIS standard △DT4 ) was produced as a matrix. Then, from this composite material, an outer diameter of 25.6IllI111 and an inner diameter of 20.011111. Five cylindrical test pieces having a length of 1,611,1111 mm and one end face as the surface to be tested were formed, and the surface roughness of the surface to be tested of each test piece was finished to 0.6 μRz by grinding.

Four parts were then formed on the surface of the matrix of the tested surface of the three cylindrical specimens by electrolytic etching performed using an aqueous nitric acid solution. FIG. 5 is a schematic diagram showing a cross section of the thus formed test piece near the surface to be tested.
1 indicates alumina-silica fibers as reinforcing fibers, 22 indicates an aluminum alloy as a matrix, and 23 indicates a recess.

In this case, by appropriately setting the electrolytic etching conditions, the average value Di of the depth Di of the recesses 23 appearing in any cross section of the test surface is 1.8μ, and the ratio of the depth to the opening diameter of the recesses 23 is obtained. The average value of , is also the depth Qi relative to the opening length Wi of the recess 23 appearing in any cross section of the surface to be tested.
The average value of the ratio Di/Wi is 0.02, and the exposed height Ll of the alumina-silica fibers from the surface 24 of the composite material
The average value Hi of i is 0.8μ, and the area ratio of the recess, that is, the recess 2 with respect to the reference length L of an arbitrary cross section of the composite material.
A three-sided cylindrical specimen was formed in which the percentage of the total opening quality Wi of three was 20%.

Next, these cylindrical test pieces were subjected to electrolytic etching, and cylindrical test pieces made of a composite material that were not electrolytically etched and had the depth of the recess, the exposed height of the alumina-silica fiber, and the area ratio of the recess were O. Sequentially set in a friction and wear tester, made of spheroidal graphite cast iron (JIs standard FCD70), the size is 30 x 30 x 5 ttrmr:
(7) A flat plate test piece with Iflj (30 x 30 mm) as the test surface, or molybdenum by plasma spraying with the same strips as in Example 1 with the same dimensions and the test surface. Alternatively, the cylindrical test piece was rotated by contacting it with the surface to be tested of a flat plate test piece coated with cast iron, supplying room temperature lubricant oil (Castle 7-Ta Aile 5AE30) to the contact area of the test piece. While rotating at 1000 rpa+, the pressure cylinder m of the cylindrical test piece relative to the flat plate test piece was increased from 10 to 9 to 700 kg, thereby conducting a seizure test to measure the seizure limit load 1.

The combinations of cylindrical test pieces and flat plate test pieces in this seizure test were as shown in Table 6 below.

In addition, the surface roughness of the tested surface of each flat test piece was 1°0μ.
It was Rz.

The results of the baking test shown in Table 2 are shown in Figure 6. From Figure 6, the combination [1] seizure limit cart is combination +! ' It is much higher than the seizure limit load of E2, and the seizure limit load of combination E4 (no seizure occurs) is combination 1! E2) E3, E5
The sintering f=l is much higher than the decay load b) and therefore the combination of a composite material made of an aluminum alloy reinforced with alumina-silica fibers and spheroidal graphite cast iron coated with a sprayed layer of molybdenum. It can be seen that the combination of an electrolytically etched composite material made of an aluminum alloy reinforced with alumina-silica fibers and spheroidal graphite cast iron coated with a solvent layer of molybdenum has excellent seizure resistance. In addition, especially when comparing the combinations El and E4, it is found that if the composite material is subjected to electrolytic etching to expose the reinforcing fibers and four parts are formed between the reinforcing fibers on the surface of the composite material, the seizure resistance will be further improved. I understand.

Although not shown in the figure, when a wear test was conducted in the same manner as in Example 1 for the combinations of test pieces shown in Table 6, combinations 1 and E4N, especially combination E4. It was confirmed that it has excellent wear resistance.

Embodiment 6 FIG. 7 is an exploded vertical sectional view showing a specific embodiment of the sliding member according to the present invention, which is a combination of a piston and a piston ring for an internal combustion engine, and FIG. 8 is an exploded longitudinal sectional view showing the main parts thereof. Fig. 9 is an exploded partial longitudinal sectional view showing an enlarged piston ring (top ring).

In these figures, 1 is a piston, which is made of aluminum alloy (JIS standard 8C to A). On the side outer circumferential surface 2 of the piston 1, there are two rings that receive compression rings 4 and 5 that prevent combustion gas from leaking from the combustion chamber of the internal combustion engine through the space between the piston 1 and the cylinder wall surface of the cylinder block 3. Grooves 6 and 7 and a ring groove 9 for receiving an oil ring 8 for scraping off excess oil are formed.

In the illustrated embodiment, the lower surface 11 of the top ring groove 6 is closer to the piston head 10 along the side outer peripheral surface 2 of the piston 1.
In the lower part of the fiber molded body, the same alumina-silica fibers as those used in Example 1 are oriented in a substantially three-dimensional random manner at a volume ratio of 8%. The other parts of the piston 1 are made of a composite material 12 having an aluminum alloy (JIS standard AC8A) as a matrix.
It defines the wall surface b, and also defines the side outer peripheral surface 2 of the piston.
A part of the top land 13 and second land 14 is defined in the exposed part.

Incidentally, such a piston is used in the mold key 1 of the mold for casting it. A fiber molded body is placed on piti bottom wall soil, and its μ
Molten aluminum alloy is poured into a mold, and a plunger that fits in the mold in a liquid-tight manner pressurizes the aluminum alloy and solidifies it into a piston rough material, which is heat treated (
After T6 processing), it is processed to the specified dimensions, and then the ring groove 6 is
．． 7.9.

As described above, the piston 1 and the PP4 are in contact with each other and are relatively connected to each other.
fl] The top ring 4 is made of spheroidal graphite cast iron (JIS standard FCD70), and although not shown in the figure, the bottom surface 17 has a thickness 5 formed by plasma cutting.
It is coated with a molten tA layer of μ molybdenum (surface roughness 0.8 μRz). In particular, the illustrated embodiment is configured as a 7° keystone ring, and a molybdenum molten steel layer 15 is provided on the sliding surface of the cylinder block 3 with the cylinder wall surface.
was formed.

The piston and piston ring configured as described above are
Built into a cylinder 4-stroke diesel engine, the engine speed is 5.
5 under test conditions of 400 rpm and full engine load.
A durability test was conducted for 00 hours. For comparison purposes, a piston ring made of spheroidal graphite cast iron (JI8 standard FCC70) whose lower surface 17 was not coated with molten molybdenum Q4FJ was also subjected to 11 durability tests under the same conditions.

As a result of the test, in the case of a piston ring made of spheroidal graphite cast iron, the amount of wear on the lower surface 11 of the ring groove was 20μ, and the amount of wear on the lower surface 17 of the piston ring was 15μ; In the case of a piston ring coated with a sprayed layer of molybdenum, the amount of wear on the lower surface 11 of the ring groove is 3μ, and the amount of wear on the lower surface 17 of the piston ring is 0.
5μ, and therefore, it was recognized that the pistons and piston rings of the examples had much better wear resistance than the comparative examples.

Example 7 The alumina-silica fibers and aluminum alloy used in Example 1 above were reinforced with 10% volume fraction alumina-silica fibers oriented three-dimensionally randomly in the Ohga manner. High-pressure casting of cylinder liners made of aluminum alloy (molten metal temperature 730°C, molten metal added F)
By manufacturing the cylinder liner using an electric force of 500 kMcraQ) and enclosing the cylinder liner by gravity casting,
Two cylinder blocks for a four-cylinder, four-cycle internal combustion engine with a cylinder bore diameter of 80IIIIl were formed, and the cylinder bore of each cylinder block was finished to a surface roughness of 0.6 μRz by honing.

Next, it is made of spheroidal graphite cast iron (JIS standard FCD70), and the radially outer peripheral surface is plasma sprayed to a thickness of 15 mm.
A piston ring coated with a sprayed layer of molybdenum (surface roughness 1.0μRz) and a spheroidal graphite cast iron (JIS
A comparative example of piston rings made of current Raku FCD70) and not coated with a sprayed molybdenum layer was prepared, and these piston rings and the above-mentioned cylinder block were combined to create a 4-ki IP! A high-speed durability test was conducted for 200 hours with an I4 cycle diesel engine, engine rotation speed 600 Orl) Im, and full engine load.

As a result of this test, when the piston ring was made of spherical black #il u iron, scuffing occurred in the cylinder bore, and the cylinder bore wear was 17 μm.
On the other hand, in the case of a piston ring made of spheroidal graphite cast iron coated with a sprayed layer of molybdenum, no scuffing occurred in the cylinder bore, and the piston ring The amount of wear on the outer circumferential surface and cylinder bore was very small, less than 2.0μ, and it was therefore recognized that the cylinder liner and piston ring of the example had significantly better wear resistance than the comparative example. Ta.

Although the present invention has been described in detail with reference to several embodiments in the following, the present invention is not limited to these embodiments, and other embodiments may be incorporated within the scope of the present invention. It will be clear to those skilled in the art that this is possible.

[Brief explanation of the drawing]

1 to 4 are graphs showing the results of the wear tests of Examples 1 to 4, respectively, and FIG. 5 is a graph showing the surface portion of the fiber-reinforced metal composite material constituting the first member of the sliding member according to the present invention. A schematic diagram showing a cross section, FIG. 6 is a graph showing the results of the firing test of Example 5, and FIG. 7 is a specific example of the sliding member according to the present invention applied to a combination of a piston and a piston ring. FIG. 8 is an enlarged vertical sectional view of the main part of the embodiment shown in FIG. 7, and FIG. 9 is an enlarged view of the piston ring (top ring). A partial vertical cross-sectional view is shown below. 1... Piston, 2... Side outer peripheral surface, 3... Cylinder liner, 4... Top ring, 5... Second ring. 6...Top ring iM, 7...Kantling i
:4,8...A illing, 9...ring iM, 1
0... Screw 1 head, 11... Bottom surface of top ring groove, 12... Composite material, 13... Top land, 14... Second land, 15... Molybdenum sprayed layer, 17...・Lower surface of top ring, 21...Alumina-silica fiber, 22...Aluminum alloy, 23
...Concave portion, 24...Surface portion Applicant: Toyota Motor Corporation Agent, Patent Attorney
Akii j Chang Yi Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 2! Alumina-silica fiber 23 recesses Fig. 6

Claims (4)

[Claims] (1) A sliding member consisting of a first member and a second member that are in contact with each other and slide relative to each other, and the sliding surface portion of at least the first member relative to the second member is 40W.
It is composed of a fiber-reinforced metal composite material having a volume ratio of 3 to 30% alumina-silica fibers having a composition of t% or more Al_2O_3 and the remainder substantially SiO_2 as reinforcing fibers and an aluminum alloy or magnesium alloy as a matrix. At least the sliding surface of the second member relative to the first member is made of metal coated with a sprayed layer of molybdenum. (2) The sliding member according to claim 1, wherein the thermal sprayed layer has a surface roughness of 1.2 μRz or less. (3) In the sliding member according to claim 1 or 2, the sliding member is an internal combustion engine, the first member is a cylinder liner, and the second member is a cylinder liner. A sliding member characterized in that the member is a piston ring. (4) In the sliding member according to any one of claims 1 to 2, the sliding member is an internal combustion engine, the first member is a piston, and the second member is a piston. is a sliding member characterized by being a piston ring.