JPS6353224A - Sliding member - Google Patents

Abstract

PURPOSE:To obtain a sliding member excellent in wear resistance, seizure resistance, etc., in both of the undermentioned members, by constituting, as to mutually abutting and sliding primary and secondary members, the primary member of a composite material consisting of an Al alloy or Mg alloy reinforced with Al2O3-SiO2 fiber into a composite state and also constituting the secondary member of ceramic. CONSTITUTION:In the above primary member, at least the sliding surface part which slides on the secondary member is constituted of a fiber-reinforced metallic composite material in which 3-30vol% of Al2O3-SiO2 fiber is used as fiber reinforcement and an Al or Mg alloy is used as matrix. Further, in the secondary member, at least the sliding part which slides on the primary member is constituted of ceramic selected from Si3N4, SiC, and ZrO2. The desired sliding member is constituted of both members mentioned above. Moreover, it is necessary that above-mentioned Al2O3-SiO2 fiber has a composition consisting of >=40vol% Al2O3 and the balance essentially SiO2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application 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. The second member is made of a composite material made of aluminum alloy or magnesium alloy reinforced with alumina-silica fibers, and the second member is made of ceramic.

2. Description of the Related Art In a sliding member made up of two members that come into contact with each other and slide relative to each other, the amount of wear on 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 reinforced with inorganic fibers such as silica fibers, and the other member is made of steel of a predetermined hardness, thereby improving the frictional and sliding properties of the sliding member. Attempts are being made to improve this.

Problems to be Solved by the Invention However, in a sliding member consisting of two members that come into contact with each other and slide relative to each other, if one of the members is made of a fiber-reinforced metal composite material, the other Depending on the material of one member, wear of the other member may increase, and problems such as seizure may occur between these members.

The inventors of the present application have proposed that in 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, the first member uses alumina-silica fiber as a reinforcing fiber. In cases where the second member is made of a composite material and the second member is made of ceramic, various experimental studies have been carried out regarding the appropriate characteristics of the ceramic that makes up the second member. As a result, it was found that a specific ceramic made of ceramic is preferable.

The present invention is based on the knowledge obtained as a result of various experimental studies conducted by the inventors of 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 with alumina-silica fibers as reinforcing fibers and an aluminum alloy or magnesium alloy as a matrix, and the second member is made of a specific ceramic. The object of the present invention is to provide a sliding member having excellent wear resistance and seizure resistance.

Means for Solving the Problems According to the present invention, the above-mentioned object is achieved by providing a sliding member consisting of a first member and a second member that abut each other and slide relative to each other; The sliding surface of at least one member relative to the second member has an AI of 40 yt% or more AI 203
, the remainder having a composition of substantially 8102, a volume fraction of 3 to 3
It is made of a fiber-reinforced metal composite material with 0% alumina-silica fibers as reinforcing fibers and aluminum alloy or magnesium alloy as a matrix, and at least the sliding surface portion of the second member relative to the first member is 5j3.
This is achieved by a sliding member made of a ceramic selected from the group consisting of N4, SiC, and Z'02.

Effects and Effects of the Invention According to the present invention, the sliding surface of the first member relative to at least the second member is reinforced with alumina-silica fibers having a volume ratio of 3 to 30%, and a matrix of aluminum alloy or magnesium alloy. The sliding surface of the second member relative to at least the first member is made of a ceramic selected from the group consisting of Si3N4, SIC, and ZrO2, which will be explained later. As is clear from the results of experimental studies conducted by the inventors of the present application, it is possible to obtain a sliding member with excellent wear resistance and seizure resistance of the two members.

According to the results of experimental research conducted by the inventors, 5i
iN4, SiC, and Zr 02 are ceramics suitable for constructing sliding members in combination with the above-mentioned fiber-reinforced metal composite materials, but the porosity of these ceramics is 2.
%, the sliding surface has a surface roughness of 1 or 2 as described below.
It becomes difficult to process the ceramic to below μRz, and therefore the wear resistance of the ceramic becomes insufficient. Therefore, according to one detailed feature of the invention, the porosity of the ceramic constituting the second member is set to 2% or less.

Also, according to the results of experimental research conducted by the inventors of the present application,
The second member is Si: + N4, Si C, or ZrO2
When the second member is made of ceramic, even if the surface roughness of the sliding surface of the ceramic is relatively large, compared to the case where the second member is made of metal with poor wear resistance, Although the amount of wear on the first and second members can be reduced,
In particular, when the surface roughness of the ceramic sliding surface is 1.2 μRz or less, the amount of wear of the two members can be suppressed to a small value. Therefore, according to another detailed feature of the invention, the surface roughness of the sliding surface of the second member is set to 1.2 μRz or less.

Furthermore, according to the results of experimental research conducted by the inventors of the present application,
By electrolytically etching the sliding surface of the first member, a part of the alumina-silica fibers is exposed on the sliding surface, and a recess is formed on the surface of the matrix between the alumina-silica fibers exposed on the sliding surface. 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, It is used with depressions formed on the surface of the matrix between the alumina-silica fibers exposed on the sliding surface.

Furthermore, alumina as a reinforcing fiber of the composite material of the second member.
If the Alph3 content of the silica-based fibers, that is, the fibers containing Al2O3 and SiO2 as main components, is less than 40 wt%, the wear resistance of the composite material cannot be sufficiently improved. Therefore, in the present invention, the Al2O3 content is 40w.
t% or more of alumina-silica fiber is used. The alumina-silica fibers may be either long fibers or short fibers, and have an average fiber diameter of 100 μm or less, particularly 1 to 40 μm.
It is preferable that it is about μ.

Furthermore, if the volume fraction of the alumina-silica fiber is less than 5%, especially less than 3%, the wear resistance of the composite material cannot be sufficiently improved; If it exceeds 15%, especially 30%, the amount of wear of the composite material and the second member increases. Therefore, the volume fraction of alumina-silica mtl is 3 to 30%, preferably 3 to 15%.
Set to %. 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 direction of unidirectional orientation or the two-dimensional random orientation plane.

Further, the second member may be formed by any method, but
It is preferable to form the ceramic powder by sintering ceramic powder since the porosity can be controlled relatively easily.

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

Example 1 A sliding member consisting of two members that come into contact with each other and slide relative to each other, one of which is made of a fiber-reinforced metal composite material with alumina-silica fibers as reinforcing fibers and aluminum alloy as a matrix. The wear test and seizure test conducted on a sliding member made of ceramic, and the other member made of ceramic, were compared with the wear test and seizure test performed on a sliding member made of a combination of other materials. This will be explained in comparison with the test.

First, alumina with an average fiber diameter of 2.8μ and an average fiber length of 6μ.
Silica fibers (55 wt% Al: 03, remainder substantially SiO2) form a fiber molded body oriented in a substantially three-dimensional random manner, and high-pressure casting (temperature of molten metal An aluminum alloy (JI
A composite material having S standard AC8A) as a matrix was manufactured. Next, from this composite material, a number of flat test specimens having a size of 16×6×b and one surface (16×6 mm) as the test surface were prepared. For comparison purposes, a large number of flat plate test pieces were prepared that were made only of aluminum alloy (JIS standard AC8A) that was not reinforced with alumina-silica fibers and had the same dimensions as the above-mentioned flat plate test pieces.

In addition, Si3N4 powder with an average particle size of 1.0μ and a small amount of Y2O
3 powder, MgA+, and 04 powder at room temperature, and then sintered at 1750°C in a non-oxidizing atmosphere, an outer diameter of 35 mm, an inner diameter of 30 ffIffl,
Cylindrical specimen made of Si3N4 with a width of 10 mm (porosity 1.0
%) and molded a mixed powder of Zr 04 powder with an average particle size of 0°5μ and a small amount of Y403 powder at room temperature.
ZrO2 with the same dimensions by sintering at 650°C
After forming a mixed powder of SiC powder with an average particle size of 0.3μ and a small amount of B powder and C powder at room temperature, a cylindrical test piece (porosity 1.0%) was formed. In 2
SIC'7 of the same size by sintering at 100℃
After forming a cylindrical test piece of A (porosity 1.1%) and molding AI = 03 powder with an average particle size of 0.4μ at room temperature,
AI 20 with the same dimensions by sintering at 700℃
A cylindrical test piece (porosity: 1.0%) manufactured by No. 3 was formed.

Next, these flat plate test pieces were sequentially set in a friction and wear tester, and each of the above-mentioned ceramic cylindrical test pieces serving as a mating member or a cylindrical test piece with an outer diameter of 35 mm, an inner diameter of 30 fflI111, and a width of 100
The end face of a cylindrical test piece made of No. 1111 spheroidal graphite cast iron (JIS standard IFcD70) was brought into contact with the test piece, and lubricating oil (castle motor oil 5
W-30), load 60 kg, rotation speed 16
A wear test was conducted in which a cylindrical test piece was rotated for 1 hour in Orpm.

The combinations of the flat plate test piece and the cylindrical test piece are as shown in Table 1 below, and the surface roughness of the test surface of the cylindrical test piece of each combination was all 1.2 μRz.

夷1 The results of this wear test are shown in Figure 1. 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 amount mff1g) of the cylindrical test piece, which is the mating material (see Figures 2 to 3 below). Fifth
The same applies to the figure).

From FIG. 1, it can be seen that the wear amounts of the flat plate test pieces of combinations Aδ to A Iff are very high values, and the wear amounts of the cylindrical test pieces of combinations A5 and Al11 are relatively high values.

In addition, the wear amount of the flat plate test piece of combination A1-A3 and combination A
From the comparison with the wear amount of the flat plate test piece in No. 4, when the constituent material of the cylindrical test piece is Si3N4, Si C, Zr O:, the wear amount of the flat plate test piece is lower than when the constituent material is Al2O3. It can be seen that is a small value. Thus, a flat plate specimen made of an aluminum alloy reinforced with alumina-silica fibers and S13N4, SiC, and Zr
It can be seen that in the case of the combination Al-A3 with a cylindrical test piece made of O2, the wear amount of both the flat plate test piece and the cylindrical test piece is smaller than in the case of other combinations.

In addition, the test piece combinations A1 to A1 shown in Table 1 above
Regarding 0, 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 while the cylindrical test piece was rotated at a rotation speed of 100 Orpm, the cylindrical test piece was attached to the flat plate test piece. suppressing load of 10kg
The load was increased to 700 kg, and a seizure test was conducted to measure the maximum seizure load.

As a result of this test, it was confirmed that the seizure limit load of combinations A1-A3 was higher than any other combination, and that these combinations also had excellent seizure resistance.

Example 2 In the same manner as in Example 1 above, the volume ratio was 896.
Alumina oriented in a substantially three-dimensional random manner
Silica fiber (same as the alumina-silica fiber used in Example 1) was used as the reinforcing fiber, and magnesium alloy (J
High-pressure casting of a composite material with IS standard MC2) as a matrix (temperature of molten metal 700°C1 pressure force against molten metal 80°C)
A large number of flat test specimens having the same dimensions as in Example 1 were prepared from the composite material.

Next, with respect to these flat test pieces, a wear test and a seizure test were conducted using the test piece combinations shown in Table 2 below in the same manner and under the same conditions as in Example 1. In addition, combination B shown in Table 2 below! The cylindrical test pieces of ~B4 were formed in the same manner and under the same conditions as the combinations A1-A4 shown in Table 1 above, and the surface roughness was adjusted. The surface roughness of the test surface was 1°2 μRz.

Table 2 The results of this wear test are shown in Figure 2. From FIG. 2, it can be seen that combination B! The wear amount of ~B3 is a low value of 5 for both the flat plate test piece and the cylindrical test piece, and therefore the composite material made of a magnesium alloy reinforced with alumina-silica fiber and St
, Si C1 and ZrO2 are also found to have excellent wear resistance.

Although not shown in the figure, the results of the seizure test showed that the combination of a composite material made of magnesium alloy reinforced with alumina-silica fibers, Si3N4.5iC1, and ZrO2 also has excellent seizure resistance. was confirmed.

Example 3 In the same manner as in Example 1 above, alumina fibers (95 wt% Al 203 , the remainder substantially S i O
2) Use aluminum alloy (JIS standard AI) C10) as reinforcing fibers (average fiber diameter 3.2μ, average fiber length 8am)
High-pressure casting of a composite material with a matrix of
2), and a large number of flat test pieces having the same dimensions as in Example 1 were prepared from the composite material.

Next, with respect to these flat test pieces, a wear test and a seizure test were conducted using the test piece combinations shown in Table 3 below in the same manner and under the same conditions as in Example 1. The cylindrical test pieces of combinations 01 to C4 shown in Table 3 below were formed in the same manner and under the same conditions as combinations A and -A4 shown in Table 1 above, and the surface roughness was adjusted. The surface roughness of the test surface of the cylindrical test piece of combination C5 is 1.
It was ゜2μRz.

Table 3 The results of this wear test are shown in Figure 3. From Figure 3, the wear amount of combinations 01 to C3 is lower than that of combinations C4 and C5 for both the flat plate specimen and the cylindrical specimen, and therefore, the wear amount is lower than that of the aluminum alloy reinforced with alumina fiber. Composite materials such as SI3 N4, SIC,
It can be seen that the combination with ZrO2 also has excellent wear resistance.

Although not shown in the figure, the results of the seizure test showed that the combination of a composite material made of aluminum alloy reinforced with alumina fibers and Si3N4, SiC, and ZrO2 also has excellent seizure resistance. was confirmed.

Example 4 Alumina fibers (same as the alumina fibers used in Example 3) were oriented in a substantially three-dimensional random manner at a volume fraction of 6% in the same manner as in Example 1 above. ) as reinforcing fibers and a magnesium alloy (JIS standard MC2) as a matrix by high-pressure casting (molten metal temperature 7
Pressure force 800 kg/cm for molten metal at 00°C
), and a large number of flat test specimens with the same dimensions 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 combinations shown in Table 4 below.

The cylindrical test pieces of ~D4 were formed in the same manner and under the same conditions as the combinations A1-A4 shown in Table 1 above, and the surface roughness was adjusted. The surface roughness of the test surface was 1°2 μRz.

Table 4 The results of this wear test are shown in Figure 4. From Fig. 4, the wear amount of combinations D1 to D3 is lower than that of combinations D4 and D5 for both the flat plate specimen and the cylindrical specimen. A composite material consisting of S l 3 N4, S I
It can be seen that the combination with C- and ZrO2 also has excellent wear resistance.

Although not shown in the figure, the results of the seizure test showed that the combination of a composite material made of magnesium alloy reinforced with alumina fibers, Sl 3 N 4 , SIC, and ZrO2 also had excellent seizure resistance. It was confirmed that there is.

Example 5 In the test piece combination corresponding to the test piece combination A1 of Example 1, the surface roughness of the test surface of the cylindrical test piece was changed by changing the grinding conditions for the test surface of the cylindrical test piece. 0.4μRz, 0.8μRz, 1.0μRz, 1.2
A wear test was conducted in the same manner and under the same conditions as in Example 1, with the surface roughness of the flat plate specimen set at 1.6 μRz and 1.4 μR2, 2,0 μRz.

The results of this wear test are shown in FIG.

From Figure 5, the surface roughness of the test surface of the cylindrical test piece is 1.2.
It can be seen that the wear amount of both the flat plate test piece and the cylindrical test piece is small when the surface roughness is less than μRz, and therefore, it is preferable that the surface roughness of the ceramic is 1.2 μRz or less.

When the same abrasion test as in this example was conducted on the test piece combinations A2 and A3 of Example 1, the same results as shown in FIG. 5 were obtained.

Example 6 A fiber molded article was formed in which the same alumina-silica fibers as those used in Example 1 were oriented in a substantially three-dimensional random manner. By high-pressure casting (temperature of molten metal 730℃, pressure applied to molten metal 500 kg/cII12), the volume ratio is 8.
% of alumina-silica fibers as reinforcing fibers and an aluminum alloy (JIS Kiraku ADT4) as a matrix. Next, from this composite material, the outer diameter is 25.6
■. Five cylindrical test pieces with inner diameter 20.011111% length 16 mm and one end face as the test surface were formed, and the surface roughness of the test surface of each test piece was reduced to 0.6μ by grinding.
Finished in Rz.

Next, recesses were formed on the surface of the matrix of the test surface of the three cylindrical test pieces by electrolytic etching using an aqueous nitric acid solution. FIG. 6 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 four portions 23 appearing in an arbitrary cross section of the test surface is 1.8μ, and the ratio of the depth to the opening diameter of the recess 23 is obtained. , that is, the depth DI relative to the opening length Wl of the recess 23 appearing in an arbitrary cross section of the surface to be tested.
The average value of the ratio D1/W1 is 0.02, the average value H1 of the exposed height H1 of the alumina-silica fibers from the surface 24 of the composite material is 0.8μ, and the area ratio of the recesses, that is, the Three cylindrical test pieces were formed in which the percentage of the ratio of the total opening length Wi of the recess 23 to the reference length of an arbitrary cross section was 2096.

Next, these cylindrical specimens were subjected to electrolytic etching, and cylindrical specimens made of a composite material in which no electrolytic etching was performed, and therefore the depth of the four parts, the exposed height of the alumina-silica fibers, and the area ratio of the recessed parts were 0. Si3N4 (porosity 1.0%), Alpha
3 (porosity 1°096), spheroidal graphite cast iron (JIS
Consisting of KIRAKU FCD70), the size is 30X30X5m.
m, one surface (30 x 30 mm) is brought into contact with the surface to be tested of a flat plate test piece, and the contact area of these test pieces is filled with room temperature lubricating oil (castle motor oil 5.
AE30) and rotate the cylindrical test piece at 11,000 r.
A seizure test was conducted to measure the maximum seizure load by increasing the suppressing load of the cylindrical test piece relative to the flat test piece from 10 kg to 700 kg while rotating at a speed of

The combinations of cylindrical test pieces and flat plate test pieces in this seizure test were as shown in Table 5 below.

In addition, the surface roughness of the tested surface of each flat test piece was 0°8μ.
It was Rz.

Table 5 The results of this seizure test are shown in Figure 7. From Fig. 7, the maximum seizure load of combination El is much higher than the maximum seizure load of combination E2, and the maximum seizure load of combination E4 (no seizure occurs) is the maximum seizure load of combinations E2, E3, and E5. The load is much higher than the limit load, therefore the combination of Si3Na with a composite material made of an aluminum alloy reinforced with alumina-silica fibers, and the electrolytically etched composite material made of an aluminum alloy reinforced with alumina-silica fibers. It can be seen that the combination of Si 3 N4 and Si 3 N4 has excellent seizure resistance. Furthermore, especially from the comparison between combinations El and E4, it was found that the seizure resistance could be further improved by subjecting the composite material to electrolytic etching to expose the reinforcing fibers and forming recesses between the reinforcing fibers on the surface of the composite material. I understand.

Although not shown in the plan view, when a wear test was conducted on the combinations of test pieces shown in Table 5 above in the same manner as in Example 1, combinations El and E4, especially combination E4. It was confirmed that it also has excellent wear resistance.

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

[Brief explanation of drawings]

FIGS. 1 to 5 are graphs showing the results of the wear tests of Examples 1 to 5, respectively, and FIG. 6 is one example of the fiber-reinforced metal composite material constituting the first member of the sliding member according to the present invention. FIG. 7 is a schematic diagram showing a cross section of the surface portion of the example, and FIG. 7 is a graph showing the results of the seizure test of Example 6. 21...Alumina-silica fiber, 22...Aluminum alloy, 23...Concave portion, 24...Surface portion Applicant: Toyota Motor Corporation Representative Patent Attorney Masaki Akashi Figure 3 Figure 4 Figure 5 Wear amount (mg) Figure 6 Figure 7

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 the first member with respect to at least the second member is 40 mm.
It is composed of a fiber-reinforced metal composite material in which the reinforcing fibers are alumina-silica fibers with a volume ratio of 3 to 30% having a composition of wt% or more Al_2O_3 and the remainder substantially SiO_2, and the matrix is an aluminum alloy or a magnesium alloy. At least the sliding surface of the second member relative to the first member is made of Si_3N_4, SiC and Zr.
A sliding member made of any ceramic selected from the group consisting of O_2. (2) The sliding member according to claim 1, wherein the ceramic has a porosity of 2% or less. (3) In the sliding member according to claim 1 or 2, the surface roughness of the sliding surface of the second member is 1.2μ.
A sliding member characterized in that Rz or less. (4) In the sliding member according to any one of claims 1 to 3, the sliding surface of the first member is electrolytically etched so that a part of the alumina-silica fiber is removed. is exposed on the sliding surface, and a recess is formed on the surface of the matrix between the alumina-silica fibers exposed on the sliding surface.