JPH0587476B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to high-temperature sliding members used as seal materials, bearing materials, etc., and a sliding method therefor. This invention relates to a ceramic high-temperature sliding member whose high-temperature sliding properties have been improved by modifying it, and a method for sliding the same. [Conventional technology and its problems] Conventionally, heat-resistant metal materials made of cobalt (Co)-based, nickel (Ni)-based, etc. alloys have been used as sliding members such as seal materials and bearing materials in high-temperature atmospheres. It is being However, from the viewpoint of heat resistance such as oxidation resistance and high-temperature strength, the use temperature is currently limited to about 800°C. Therefore, efforts are being made to utilize ceramic materials, which have better physical, chemical, and mechanical properties than metals in high-temperature atmospheres. However, this ceramic material, which is generally considered to be a wear-resistant material, actually has low wear resistance and has the disadvantage that wear increases significantly as the temperature rises, making it difficult to use as a structural material. It is difficult to use this ceramic material as it is as a high-temperature sliding member because it has sufficient high-temperature properties. This is because when a material made of ceramics is used as a sliding member, during the sliding process in a high-temperature atmosphere, the ceramic material is worn away at local high surface pressure contact areas and abrasion powder is generated. This is because the abrasive action of and the accompanying increase in surface roughness accelerate the wear of the sliding member and the mating material. When the mating material is softer than ceramics, such as a metal material, the abrasion powder generated is easily buried, so the abrasive action of the abrasion powder is suppressed, but when the mating material is made of ceramic material, Since it has poor embeddability, wear is particularly significant and dimensional changes become severe, making it difficult to put it to practical use. In order to solve this problem, various developments have been made in the past, and several sliding members with improved wear resistance have been proposed. One such material is a silicon nitride material obtained by adding boron nitride (BN), which is a solid lubricant, to the raw material for ceramics and firing the surface layer using this raw material (Japanese Patent Application Laid-Open No. 1983-1999- 137375). However, this ceramic material
Although it is true that the wear resistance has been improved to some extent, there is a problem in that the inherent strength of the ceramic material is reduced. Therefore, the present inventors conducted intensive research to solve the above-mentioned problems of the prior art, and as a result of conducting various systematic experiments, they came up with the present invention. [Object of the Invention] An object of the present invention is to provide a sliding member with excellent wear resistance in a high-temperature atmosphere and a method for sliding the same. [Structure of the Invention] The high-temperature sliding member of the present invention includes a base material made of oxide ceramics, and one of chromium, manganese, iron, cobalt, nickel, copper, and silver or an alloy thereof is physically vapor-deposited on the surface of the base material. A high-temperature sliding member consisting of a metal film obtained by The present invention is characterized in that wear of the ceramic member and the base material is prevented by sliding a ceramic member as a mating member on the surface of the sliding part (hereinafter referred to as the first invention). . The sliding method of a high temperature sliding member of the present invention is a method of sliding a sliding member made of a pair of ceramic members at high temperature, in which at least one member is placed on the surface of a ceramic base material made of oxide ceramics or nitride ceramics. Chromium, manganese,
A metal film made of one of iron, cobalt, nickel, copper, and silver or an alloy thereof is coated by physical vapor deposition to form a sliding part on the surface, and the sliding part is heated to oxidize the sliding part. form a layer of matter,
By sliding a ceramic member as a mating material on the oxide layer of the sliding part in a high-temperature atmosphere of 500°C or higher and promoting frictional surface familiarity between the ceramic member and the sliding part of the metal film, the ceramic This invention is characterized by preventing wear of the members and the base material (hereinafter referred to as the second invention). Below, the configuration of the present invention will be explained in more detail. First, the high temperature sliding member of the first invention will be explained. The base material in the first invention is a base material for a high-temperature sliding member, and is an oxide ceramic sintered body manufactured using oxide as a main raw material, and includes alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ) or other oxide ceramics are used. This oxide ceramic has excellent oxidation resistance, and although its high-temperature strength is slightly inferior to silicon nitride and silicon carbide, it has superior physical, chemical, and mechanical properties in a high-temperature atmosphere compared to conventional heat-resistant alloys. have In addition, the metal film formed on the surface of the sliding part of the base material made of oxide ceramics becomes a lubricant when softened or melted at high temperatures or oxidized in the atmosphere, making it resistant to the ceramic base material. A thin metal film that imparts wear resistance, made from one of chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), or an alloy thereof. It is a metal film. Here, the thickness of this metal film is such that it imparts wear resistance to the oxide ceramic material as the base material of the high-temperature sliding member, and it also reduces the surface roughness of the oxide ceramic base material. There is no particular limitation as long as the film thickness exceeds, but preferably,
It is 0.1 to 5 μm. This means that the thickness of the metal film is
If it is less than 0.1 μm, it is difficult to prevent the base material from being destroyed by the shear force generated on the friction surface during sliding, and if it exceeds 5 μm, it may cause dimensional changes due to metal melting or oxidation at high temperatures. This is because the friction becomes intense, making it difficult to function as a sliding member. Furthermore, when the oxide ceramic is a zirconia ceramic and the metal film is manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), or silver (Ag), the film thickness of the metal film is is preferably 1 μm or more. This is because the strength of zirconia ceramics decreases relatively significantly at high temperatures. In this case, wear resistance can be further improved by combining ceramics with high high temperature strength such as silicon nitride as the mating material. In addition, the metal film formed on the surface of the sliding part of the ceramic base material is softer than the base material from room temperature to high temperature, and is oxidized from the surface at high temperatures, which prevents direct contact between the ceramic base materials, especially in the early stages of friction. It plays the role of preventing friction and promoting familiarity with friction surfaces, and provides high wear resistance at temperatures above 500°C, where wear of the base material is particularly high. Furthermore, depending on the type of the ceramic base material and the metal film, the base material and the oxide of the coating metal may react to form a brittle intermetallic compound, which may limit the operating temperature. For example, when forming a Ni film on alumina ceramics, it is preferable to use an ambient temperature of up to about 900°C. This is because the operating temperature is
In the case of 1000℃, a temperature increase due to frictional heat is added, and a spinel is generated by the reaction between NiO, the divalent oxide of the metal film, and the alumina base material: NiO + Al ₂ O ₃ → NiAl ₂ O ₄ . This is because wear resistance is impaired. However, this is because the Ni oxide is only divalent, and it is a metal film that can also be a monovalent or polyvalent oxide of trivalent or higher valence, so even if spinel is formed, the coating metal alone will not be present. oxide layer is formed, giving the alumina base material excellent wear resistance even at temperatures above 1000°C. The high-temperature sliding member of the first invention includes chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), A metal film made of one type of silver (Ag) or an alloy thereof is formed. Here, the coating and formation of the metal film on the surface of the oxide ceramic substrate is performed by physical vapor deposition. This physical vapor deposition (PVD)
As mentioned above, as long as a metal film useful as a high-temperature sliding member can be coated/formed on the surface of a ceramic substrate, it does not specify a specific method, but may include vacuum evaporation, sputtering, ionization, etc. Any method such as a plating method may be used. A typical manufacturing method of the high-temperature sliding member of the first invention will be briefly described as follows. First, an oxide ceramic having desired properties according to its purpose as a high-temperature sliding member is obtained by a conventional ceramic manufacturing method and used as a base material. Next, the obtained ceramic substrate is placed in a vacuum evaporation device, a sputtering device, etc., and a desired metal is coated on the surface of the oxide ceramic substrate by a physical vapor deposition method such as a vacuum evaporation method or a sputtering method. A high temperature sliding member according to the first invention is obtained. Further, the high temperature sliding member of the first invention may be one in which an oxide layer is formed on the sliding portion of the metal film. In that case, the oxide layer is formed by heating the high temperature sliding member. Next, the sliding method of the high temperature sliding member of the second invention is as follows:
This is a method of sliding the high-temperature sliding member of the first invention and a ceramic member as a mating member at high temperature. That is, the method for sliding a high-temperature sliding member of the second invention is a method for sliding a sliding member made of a pair of ceramic members at a high temperature, in which at least one of the members is manufactured using an oxide as a main raw material. Chromium, manganese, iron, cobalt, nickel,
A metal film made of one of copper, silver, or an alloy thereof is coated by physical vapor deposition to form a sliding part on the surface, and the sliding part is heated to form an oxide layer on at least the surface of the sliding part. The ceramic member as a mating material and the oxide layer of the sliding part are made to slide in a high temperature atmosphere of 500°C or higher, including at least the sliding surface and its vicinity, and the sliding of the ceramic member and the metal film is achieved. This prevents wear of the ceramic member and the base material by promoting frictional surface familiarity with the ceramic member and the base material. At this time, the oxide layer is formed on the sliding portion of the metal film by heating at least the temperature atmosphere at or near the sliding portion to a temperature at which the metal film is oxidized. Therefore, the heating may be performed by setting only the part where the oxidized layer is to be formed to a predetermined temperature atmosphere, or to setting the atmosphere including the part to a predetermined temperature atmosphere. Further, the heating may be performed by simply generating frictional heat in the portion due to sliding with a ceramic member serving as a mating material, and setting the atmosphere containing the portion to a predetermined temperature atmosphere. [Operations and Effects of the Invention] The high-temperature sliding member of the first invention and the sliding method of the second invention have excellent wear resistance in a high-temperature atmosphere of 500° C. or higher. Further, by the sliding method of the second invention, wear due to sliding of the sliding member can be prevented even in a high temperature atmosphere of 500° C. or higher. As described above, the mechanism by which the high-temperature sliding member of the first invention and the sliding method of the second invention exhibit such effects is not necessarily clear, but it is thought to be as follows. In other words, the oxide ceramics used as the base material of the high-temperature sliding member of the present invention have excellent heat resistance, have small decreases in mechanical properties as the temperature rises, and have sufficient properties even in high-temperature atmospheres of 800°C or higher. It has strength and also has a small coefficient of thermal expansion, so the amount of thermal deformation is small. The metal film formed on the surface of the oxide ceramic base material is made of a metal or an alloy thereof that is softer than the base material, and blends well into the ceramic base material as a base. Further, at high temperatures, this metal film softens, melts, or reacts with the atmosphere to become an oxide film, which acts as a lubricant to prevent wear of the base material. When this high-temperature sliding member and method are used in a high-temperature atmosphere, the load that acts on the friction surface due to sliding is received by the underlying ceramic base material, and the shear force accompanying friction is extremely absorbed by the thin metal film on the surface that has been softened by the high temperature. or its high-temperature oxide layer. Furthermore, the sliding surface, which inevitably experiences localized high surface pressure contact or uneven contact due to machining accuracy, can be quickly adapted by deformation or slight abrasion of this oxide layer. As a result, hard wear-promoting substances such as ceramic wear particles are not generated on the sliding surface, and the wear resistance of the base material and mating material is significantly improved, which is thought to result in excellent high-temperature sliding properties. . The first and second inventions have excellent high-temperature sliding properties, heat resistance, and wear resistance, so they can be used as high-temperature sealing materials for heat exchangers, bearing materials used in molten metal, bearing materials for turbochargers, etc. It can be widely used as a sliding member and sliding method in an atmosphere. [Example] Example 1 First, a 26 x 26 x 4 mm alumina sintered body (manufactured by Kyocera Corporation: A479) was used as an oxide ceramic base material.
A hole with a diameter of 5 mm was made in the center of the flat plate, and the surface roughness was
A sample obtained by polishing to 0.05 μm Rz was prepared. Next, this ceramic base material was placed in a vacuum evaporation device (manufactured by JEOL Ltd., JEE-5B), the pressure was reduced to 10 ^-3 Pascal (Pa), and the ceramic base material was
The substrate was heated to 400° C. and vacuum evaporated using a tungsten (W) wire basket to coat the metal shown in Table 1. As a result, high-temperature sliding members according to the present invention were obtained (sample numbers 1-6, 8-1
2). For sample numbers 7 and 13 to 15, glow discharge was performed for more than 1 hour using a sputtering device with argon (Ar) gas introduced and a vacuum level of 4 Pa to coat the base material surface with nickel or iron. . A performance evaluation test of the obtained high-temperature sliding member was conducted by a friction and wear test. First, the obtained high-temperature sliding member was designated as sample plate A. Next, a 26 x 26 x 4 alumina sintered body (manufactured by Kyocera Corporation: A479) of the same quality as the ceramic base material described above was prepared.
mm, surface roughness 0.05μmRz) was processed so that one surface (friction surface part) had a protruding shape with a diameter of 25mm and a thickness of 1mm, and a hole with a diameter of 10mm was made in the center of the sample plate. It was set as B. Next, sample plate A was placed on the test piece stand on the rotating shaft side of the thrust collar type high temperature friction tester, and sample plate B was placed on the test piece stand on the pressurized shaft side, and the test conditions were as shown in Table 2. Friction and wear tests were conducted using the following methods. The results obtained are shown in Table 1. Note that the amount of wear was obtained by measuring changes in weight of test plate A and sample plate B. At that time, if sample plate A is heated to a high temperature, the metal film will be oxidized and its weight will increase, so in order to avoid this effect, the weight of the sample plate after the test with a sliding distance of 120 m and the sliding distance of 600 m
The difference between m and the weight of the sample plate after the test was used as an index of the amount of wear. Further, for Sample No. 1 and Sample No. 7, the cross-sectional profile of the wear marks on sample plate A was obtained using a stylus roughness meter. The results are shown in FIGS. 1 and 2. In the figure, 1 and 2 are sample plates A
, and 11 and 12 indicate the surfaces of the wear marks on sample plate A, respectively. For comparison, samples using an alumina sintered body (same as the ceramic base material described above) without a metal film were used as sample plates A (sample numbers C1 and C2), or sample plates A and B were used as sample plates A and B. Comparative tests were conducted in the same manner with the same configuration as above except that a silicon carbide sintered body (SiC: manufactured by Ibiden Co., Ltd.; Ibiceram, same dimensions) consisting of α-SiO and β-SiO was used (test numbers C3 to C4). I went to The obtained results are also shown in Table 1. For sample number C2, the cross-sectional profile of the wear marks on sample plate A was obtained using a stylus roughness meter. The results are shown in FIG. In the figure, 3 indicates the outermost surface of the sample plate A, and 13 indicates the surface of the abrasion marks on the sample plate A, respectively.

【table】

【table】

【table】

[Table] As is clear from the above results, when the high-temperature sliding member according to the present invention is used, it is found that the wear resistance is excellent in a high-temperature atmosphere. Example 2 First, as an oxide ceramic base material, 3 mol
%Y ₂ O ₃ Partially stabilized zirconia (ZrO ₂ : Kyocera Corporation)
A hole with a diameter of 5 mm was drilled in the center of a 26 x 26 x 4 mm flat plate (manufactured by Z201) and polished to a surface roughness of 0.1 μmRz. Next, vacuum evaporation was performed on this ceramic base material using the same vacuum evaporation apparatus as in Example 1, and the third
The metals shown in the table were coated. As a result, a high temperature sliding member according to the present invention was obtained (sample number 16,1
9). For sample No. 20, a sputtering device was used, argon (Ar) gas was introduced, the pressure was 4 Pa, and glow discharge was performed for more than 1 hour depending on the film thickness to coat the surface of the base material with nickel. Next, the obtained high-temperature sliding member was designated as sample plate A,
One surface (friction surface part) of a zirconia sintered body (manufactured by Kyocera Corporation: Z201: 26 x 26 x 4 mm, surface roughness: 0.1 μm Rz), which is the same as the ceramic base material described above, is 25 mm in diameter and 1 mm thick. The disk was processed to have a protruding shape, and a hole with a diameter of 10 mm was made in the center to prepare sample plate B. In addition, for sample number 19, a silicon nitride sintered body (manufactured by Kyocera Corporation: SN220: similar shape to the above-mentioned sample plate B) was used as sample plate B. Next, sample plate A was placed on the test piece stand on the rotating shaft side of the high-temperature friction tester of the draft collar type, and sample plate B was placed on the test piece stand on the pressurized shaft side, and the test conditions shown in Table 2 were set. Friction and wear tests were conducted using the following methods. The results obtained are shown in Table 3. Note that the method for measuring the amount of wear is the same as in Example 1. In addition, for sample number 18, sample plate A
The cross-sectional profile of the wear scar was obtained using a stylus roughness meter. The results are shown in FIG. In the figure, 4 indicates the outermost surface of the sample plate A, and 14 indicates the surface of the abrasion marks on the sample plate A, respectively. For comparison, a comparative test was conducted with the same configuration as above except that a zirconia sintered body (same as the above-mentioned ceramic base material) without a metal film was used as sample plate A (sample numbers C5 to C7). Ivy. The obtained results are also shown in Table 3. For sample number C7, the cross-sectional profile of the wear marks on sample plate A was obtained using a stylus roughness meter. The results are shown in FIG. In the figure, 5 indicates the outermost surface of the sample plate A, and 15 indicates the surface of the abrasion marks on the sample plate A, respectively.

【table】

[Table] As is clear from the above results, when the high-temperature sliding member according to the present invention is used, it is found that the wear resistance is excellent in a high-temperature atmosphere.

[Brief explanation of the drawing]

The figure is a diagram showing the cross-sectional profile of the wear scar of sample A after the friction and wear test in Example 1 or Example 2 of the present invention, and Figures 1 to 5 are for sample numbers 1, 7C2, 18, and 18, respectively. It is a diagram of C7. 1, 2, 3, 4, 5... Uppermost surface of sample plate A, 1
1, 12, 13, 14, 15... Surface of wear marks on sample plate A.

Claims (1)

[Scope of Claims] 1. A base material made of oxide ceramics, and a metal film obtained by physically vapor depositing one of chromium, manganese, iron, cobalt, nickel, copper, and silver or an alloy thereof on the surface of the base material. , a high-temperature sliding member consisting of a sliding part formed on the surface of the metal film, by sliding a ceramic member as a mating material on the surface of the sliding part in a high-temperature atmosphere of 500°C or higher. A high-temperature sliding member characterized by preventing abrasion of a ceramic member and a base material. 2. The high-temperature sliding member according to claim 1, wherein the metal film has a thickness of 0.1 μm to 5 μm. 3. The high-temperature sliding member according to claim 1, characterized in that an oxide layer is formed on the sliding portion of the metal film. 4. The high-temperature sliding member according to claim 1, wherein the oxide ceramic is an alumina ceramic or a zirconia ceramic. 5. In a method of sliding a pair of sliding members made of a pair of ceramic members at high temperature, at least one member is coated on the surface of a ceramic base material made of oxide ceramics with one of chromium, maganese, iron, cobalt, nickel, copper, silver or the like. A metal film made of the alloy is coated by physical vapor deposition to form a sliding part on the surface, and an oxide layer is formed on the sliding part by heating the sliding part, and an oxide layer is formed on the sliding part in a high temperature atmosphere of 500 ° C or more. At the bottom, a ceramic member as a mating material is slid on the oxide layer of the sliding part to promote frictional surface familiarization between the ceramic member and the sliding part of the metal film, thereby reducing wear of the ceramic member and the base material. A method for sliding a high-temperature sliding member, characterized by preventing the above.