JP2009286678A - Ceramic-based composite material, method for producing the same, rolling member and rolling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic-based composite material which is light in weight and is excellent in mechanical physical properties and wear resistance, to provide a method for producing the ceramic-based composite material, to provide a rolling member which is light in weight and is excellent in mechanical physical properties and wear resistance, and to provide a rolling device which has long service life. <P>SOLUTION: At least one selected from the inner ring 1, outer ring 2 and rolling element 3 of a deep groove ball bearing is composed of a ceramic-based composite material. This ceramic-based composite material is composed of: at least one of ceramic selected from silicon nitride, silicon carbide, aluminum oxide, silicon oxide and zirconium oxide by 60 to 80 mass%; and a metal by ≤40 to ≥20 mass%. Then, the ceramic-based composite material is produced by sintering a molding obtained by mixing porous ceramic powder having pores in a nanometer order and metal powder and molding the mixed powder by injection molding or die casting. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a ceramic matrix composite material that is lightweight and excellent in mechanical properties and wear resistance, and a method for producing the same. The present invention also relates to a rolling member and a rolling device made of a ceramic matrix composite material.

Conventionally, various composite materials made of ceramics and metals are known. For example, Patent Documents 1 to 3 disclose composite materials in which ceramic particles are dispersed in an aluminum alloy.
In the composite materials described in Patent Documents 1 to 3, an aluminum alloy is a main component, and ceramic particles added for the purpose of strengthening or the like are dispersed in the aluminum alloy. Moreover, these composite materials are manufactured by pulverizing a molten aluminum alloy containing ceramic particles by an atomizing method, and molding and solidifying the obtained powder.
Japanese Patent Laid-Open No. 5-78708 JP-A-5-51663 JP-A-5-43964

However, since the composite materials described in Patent Documents 1 to 3 are mainly composed of an aluminum alloy, mechanical properties such as Young's modulus are insufficient for use as a material for rolling members and rolling devices. .
Accordingly, an object of the present invention is to solve the above-described problems of the prior art, and to provide a ceramic matrix composite material that is lightweight and excellent in mechanical properties and wear resistance, and a method for producing the same. Another object of the present invention is to provide a rolling member that is lightweight and has excellent mechanical properties and wear resistance. Another object is to provide a rolling device having a long life.

In order to solve the above problems, the present invention has the following configuration. That is, the ceramic matrix composite material according to the present invention has a ceramic content of 60% by mass to 80% by mass and a metal content of 40% by mass or less 20% of at least one of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide. It is characterized by being comprised by the mass% or more.
With such a configuration, the ceramic matrix composite material of the present invention is lightweight and excellent in mechanical properties and wear resistance. If the ceramic content exceeds 80% by mass (that is, if the metal content is less than 20% by mass), the metal acts as an impurity and becomes a starting point of destruction, and the ceramic matrix composite material may become brittle. On the other hand, if the ceramic content is less than 60% by mass (that is, if the metal content exceeds 40% by mass), the hardness, strength, and wear resistance may be insufficient.

  In such a ceramic matrix composite material of the present invention, the metal is preferably at least one of aluminum, an aluminum alloy, and steel. In the ceramic matrix composite material of the present invention, the ceramic is preferably a porous body. Furthermore, the ceramic matrix composite material of the present invention preferably has a Vickers hardness of Hv 900 or more and a Young's modulus of 200 GPa or more.

Furthermore, the method for producing a ceramic matrix composite material according to the present invention comprises a porous ceramic powder having at least one kind of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide and having pores in the nanometer order. The metal powder is mixed, and a molded product obtained by molding the mixed powder by injection molding or die molding is sintered. In the method for producing a ceramic matrix composite material according to the present invention, a porous ceramic powder made of at least one of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide is impregnated with a molten metal. It is characterized by.
With such a configuration, a ceramic matrix composite material that is lightweight and has excellent mechanical properties and wear resistance can be easily produced.

In these methods for producing a ceramic matrix composite material of the present invention, the metal is preferably at least one of aluminum, an aluminum alloy, and steel.
Furthermore, the rolling member according to the present invention is a rolling member in which relative rolling contact or sliding contact occurs with a counterpart member, and the ceramic matrix composite material of the present invention described above or the ceramic of the present invention described above. It is characterized by being comprised with the ceramic matrix composite material manufactured with the manufacturing method of the matrix composite material.
With such a configuration, the rolling member of the present invention is lightweight and has excellent mechanical properties and wear resistance.

Furthermore, the rolling device according to the present invention has an inner member having a raceway surface on the outer surface, and a raceway surface facing the raceway surface of the inner member on the inner surface, and is disposed outside the inner member. In a rolling device comprising an outer member and a rolling element disposed so as to be freely rollable between both raceway surfaces, at least one of the inner member, the outer member, and the rolling element, The rolling member of the present invention described above is used.
With such a configuration, the rolling device constituting the rolling device is light in weight, and has excellent mechanical properties and wear resistance. Therefore, the rolling device of the present invention has a long life.
Examples of the rolling device include a rolling bearing, a linear motion guide bearing (linear guide device), a ball screw, and a linear motion bearing.

  The inner member is an inner ring when the rolling device is a rolling bearing, a guide rail when the rolling guide bearing is the same, a screw shaft when the ball screw is the same, a shaft when the rolling bearing is also the same, Each means. In addition, the outer member is an outer ring when the rolling device is a rolling bearing, a slider when the same is a linear guide bearing, a nut when it is a ball screw, and an outer cylinder when it is also a linear bearing. means.

The ceramic matrix composite material of the present invention is lightweight and has excellent mechanical properties and wear resistance. In addition, the method for producing a ceramic matrix composite material of the present invention can easily produce a ceramic matrix composite material that is lightweight and excellent in mechanical properties and wear resistance.
Furthermore, the rolling member of the present invention is lightweight and has excellent mechanical properties and wear resistance. Furthermore, the rolling device of the present invention has a long life.

DESCRIPTION OF EMBODIMENTS Embodiments of a ceramic matrix composite material and a manufacturing method thereof, a rolling member, and a rolling device according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a partial longitudinal sectional view of a deep groove ball bearing which is an embodiment of a rolling device according to the present invention. The deep groove ball bearing shown in FIG. 1 is rotatable between an inner ring 1 having a raceway surface 1a on the outer peripheral surface, an outer ring 2 having a raceway surface 2a facing the raceway surface 1a on the inner peripheral surface, and both raceway surfaces 1a and 2a. A plurality of rolling elements (balls) 3 arranged on the bearings 4 and a cage 4 that holds the plurality of rolling elements 3 equally between the raceway surfaces 1a and 2a in the circumferential direction of the bearing. In addition, the holder | retainer 4 does not need to be provided. Moreover, you may provide sealing devices, such as a seal and a shield.

  Since the inner ring 1, the outer ring 2 and the rolling element 3 are in rolling contact or sliding contact with each other, the inner ring 1, the outer ring 2, and the rolling element 3 correspond to rolling members. In the deep groove ball bearing of this embodiment, at least one of these rolling members is made of a ceramic matrix composite material. Although all of the inner ring 1, outer ring 2, and rolling element 3 may be made of a ceramic matrix composite material, one or two members of the inner ring 1, outer ring 2, and rolling element 3 are made of a ceramic matrix composite material. And about the rolling member which is not comprised with the ceramic matrix composite material, you may comprise with steel, such as SUJ2.

  The ceramic matrix composite material includes 60% by mass or more and 80% by mass or less of ceramics composed of at least one of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide, and 40% by mass or less and 20% by mass or more of metal. It consists of Since such a ceramic matrix composite material is lightweight and has excellent mechanical properties and wear resistance, the deep groove ball bearing of this embodiment has a long life with little wear and damage.

  The metal is preferably at least one of aluminum, aluminum alloy, and steel. The ceramic is preferably a porous body. If the ceramic is a porous body, the ceramic and the metal are firmly bonded and combined. Furthermore, the ceramic-based composite material preferably has a Vickers hardness of Hv 900 or more and a Young's modulus of 200 GPa or more.

  Such a rolling member made of a ceramic matrix composite material can be manufactured by one of the following two manufacturing methods. In the first production method, a porous ceramic powder made of at least one of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide and having pores in the nanometer order is mixed with a metal powder. , And sintering a molded product obtained by molding the mixed powder by injection molding or die molding. The second manufacturing method is a method in which a porous ceramic powder made of at least one of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide is impregnated with a molten metal.

  In both the first and second production methods, the average particle size of the ceramic powder is preferably 5 μm or less in order to uniformly and strongly combine the ceramic and the metal. In the first production method, the average particle size of the metal powder is preferably 5 μm or less. Furthermore, in the first production method, ceramic powder having fine irregularities formed on the surface can be used instead of porous ceramic powder having nanometer-order pores.

Furthermore, in the first production method, the ceramic powder and the metal powder having a particle size larger than the above preferable value may be mixed after being pulverized to the above preferable value, respectively, or the particle size may be larger than the above preferable value. After mixing ceramic powder and metal powder having a large particle size, the powder may be pulverized to the above preferable value, or commercially available ceramic powder and metal powder having a particle diameter of the above preferable value may be mixed in advance. .
In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment.

For example, in the present embodiment, a deep groove ball bearing has been described as an example of the rolling device, but the present invention can be applied to various types of rolling bearings. For example, radial type rolling bearings such as angular contact ball bearings, self-aligning ball bearings, cylindrical roller bearings, tapered roller bearings, needle roller bearings, and self-aligning roller bearings, and thrust types such as thrust ball bearings and thrust roller bearings This is a rolling bearing.
Furthermore, in the present embodiment, a rolling bearing has been described as an example of the rolling device, but the present invention can be applied to various types of other rolling devices. For example, the present invention can be suitably applied to other rolling devices such as a linear motion guide bearing (linear guide device), a ball screw, and a linear motion bearing.

〔Example〕
Hereinafter, the present invention will be further described with reference to specific examples. A deep groove ball bearing having a nominal number 6206 was prepared and subjected to a rotation test to evaluate the life of the rolling element.
The deep groove ball bearing of Example 1 is a bearing in which an inner ring and an outer ring are made of SUJ2, and a rolling element is made of a ceramic matrix composite material. This ceramic matrix composite material is composed of 80% by mass of silicon oxide (specific gravity 2.2) and 20% by mass of aluminum (specific gravity 2.7), and is manufactured by powder metallurgy.

  First, porous silicon oxide powder (average particle size 1 μm) having pores having a diameter of 50 to 100 nm and pure aluminum powder (average particle size 10 μm) are uniformly mixed by an attritor (ball mill) to obtain a mixed powder. It was. The mixed powder was filled in a mold and molded by cold isostatic pressing (CIP) to obtain a spherical molded product having a diameter of 15 mm. Then, this molded product was pressurized at 500 to 700 ° C. in a nitrogen atmosphere of 3 to 10 atm to perform sintering. The specific gravity of the obtained ceramic matrix composite sphere was 2.3, which was almost equal to the theoretical value. The balls made of this ceramic matrix composite material were polished and used as rolling elements for the deep groove ball bearing of Example 1.

The deep groove ball bearing of Example 2 is the same as that of Example 1, except that the composition ratio of silicon oxide and aluminum constituting the ceramic matrix composite material is 70% by mass of silicon oxide and 30% by mass of aluminum. It is the same.
The deep groove ball bearing of Example 3 is the same as that of Example 1 except that the composition ratio of silicon oxide and aluminum constituting the ceramic matrix composite material is 60% by mass of silicon oxide and 40% by mass of aluminum. It is the same.

The deep groove ball bearing of Comparative Example 1 is the deep groove ball bearing of Example 1 except that the composition ratio of silicon oxide and aluminum constituting the ceramic matrix composite material is 95% by mass of silicon oxide and 5% by mass of aluminum. It is the same.
The deep groove ball bearing of Comparative Example 2 is the deep groove ball bearing of Example 1 except that the composition ratio of silicon oxide and aluminum constituting the ceramic matrix composite material is 40% by mass of silicon oxide and 60% by mass of aluminum. It is the same.

The deep groove ball bearing of Comparative Example 3 is the deep groove ball bearing of Example 1 except that the composition ratio of silicon oxide and aluminum constituting the ceramic matrix composite material is 10% by mass of silicon oxide and 90% by mass of aluminum. It is the same.
The deep groove ball bearing of Comparative Example 4 is the same as the deep groove ball bearing of Example 1 except that the rolling element is composed of SUJ2. In this rolling element, a SUJ2 ball is heated to 800 to 850 ° C., put into a quenching oil of 40 to 100 ° C. and quenched, tempered at 150 to 200 ° C., further polished, and stipulated in JIS B1501. Grade 28.

The deep groove ball bearing of Comparative Example 5 is the same as the deep groove ball bearing of Example 1 except that the rolling elements are made of silicon nitride. In this rolling element, α-Si ₃ N ₄ produced by an imide decomposition method, _{3 to} 10% by mass of Y ₂ O _{3 and} 3 to 10% by mass of Al ₂ O ₃ are uniformly mixed by an attritor (ball mill), This mixed powder is press-molded with 1 ton and then pressed with a cold isostatic press, further degreased at 400 to 600 ° C, sintered at 1600 to 1900 ° C, and heated at 1200 to 1700 ° C and 1000 to 2000 atmospheres. It is manufactured by sequentially performing isostatic pressing (HIP).

  The deep groove ball bearing of Comparative Example 6 is the same as the deep groove ball bearing of Example 1 except that the rolling elements are made of an aluminum alloy matrix composite material. This aluminum alloy-based composite material is obtained by pulverizing a molten aluminum alloy in which silicon carbide particles are dispersed by an atomizing method so that the average particle size of the dispersed particles is 20 μm or less. It is manufactured by warm forming and solidifying (see Patent Document 1).

These deep groove ball bearings were subjected to a rotation test under the following conditions, and the time until the rolling elements were damaged (L ₁₀ life) was measured. In addition, when damage, such as peeling of the raceway surface, occurred in the raceway, the rotation test was continued after replacing the raceway with a new one.
Load: 9702N (maximum surface pressure: 3.4 GPa)
Basic dynamic load rating: 19404N
Basic static load rating: 11270N
Rotation speed: 3900rpm
Calculated life: 20 hours Lubricant: Lubricating oil whose ISO viscosity grade is ISO VG68 (forced circulation lubrication)
As a result of the rotation test, the L ₁₀ lifetimes of the deep groove ball bearings of Examples 1 to 3 were 481 hours, 522 hours, and 475 hours, respectively. On the other hand, the L ₁₀ lifetimes of the deep groove ball bearings of Comparative Examples 1 to 6 were 15 hours, 93 hours, 38 hours, 407 hours, 113 hours, and 154 hours, respectively.

From these results, the deep groove ball bearings of Examples 1 to 3 in which the rolling elements are configured by the ceramic matrix composite material of the present invention are equal to or longer than the deep groove ball bearing of Comparative Example 4 in which the rolling elements are configured by SUJ2. It can be seen that the lifetime can be achieved. Moreover, it turns out that it is long life rather than the deep groove ball bearing of the comparative examples 5 and 6 with which the rolling element was comprised with the general ceramics and the conventional aluminum alloy matrix composite material. Since the ceramic matrix composite material of the present invention is light and high in strength and has improved brittleness which is a problem of ceramics, such excellent performance can be obtained.
Moreover, from the graph of FIG. 2 which shows the specific gravity of the ceramic matrix composite material of Example 1, SUJ2 of Comparative Example 4, and silicon nitride of Comparative Example 5, the rolling element of the deep groove ball bearing of Example 1 is made of SUJ2. It can be seen that the deep groove ball bearing of Comparative Example 4 is sufficiently lightened and has a weight equivalent to that of the deep groove ball bearing of Comparative Example 5 in which the rolling elements are made of silicon nitride.

It is a fragmentary longitudinal cross-section which shows the structure of the deep groove ball bearing which is one Embodiment of the rolling device which concerns on this invention. It is a graph which shows the specific gravity of a raw material.

Explanation of symbols

1 inner ring 1a raceway surface 2 outer ring 2a raceway surface 3 rolling element

Claims (9)

  It is composed of 60% by mass or more and 80% by mass or less of ceramics composed of at least one of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide, and 40% by mass or less and 20% by mass or more of metals. A ceramic matrix composite material.   2. The ceramic matrix composite material according to claim 1, wherein the metal is at least one of aluminum, an aluminum alloy, and steel.   The ceramic-based composite material according to claim 1 or 2, wherein the ceramic is a porous body.   The ceramic matrix composite material according to any one of claims 1 to 3, wherein the Vickers hardness is Hv 900 or more and the Young's modulus is 200 GPa or more.   A porous ceramic powder composed of at least one of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide and having nanometer-order pores is mixed with a metal powder, and the mixed powder is injection molded. Or the manufacturing method of the ceramic matrix composite material characterized by sintering the molded object shape | molded by metal mold | die shaping | molding.   A method for producing a ceramic matrix composite material, comprising impregnating a porous ceramic powder composed of at least one of silicon nitride, silicon carbide, aluminum oxide, silicon oxide, and zirconium oxide with a molten metal.   The method for producing a ceramic matrix composite material according to claim 5 or 6, wherein the metal is at least one of aluminum, an aluminum alloy, and steel.   In the rolling member in which a relative rolling contact or a sliding contact occurs with a counterpart member, the ceramic matrix composite material according to any one of claims 1 to 4 or any one of claims 5 to 7. A rolling member comprising the ceramic matrix composite material produced by the method for producing a ceramic matrix composite material according to Item.   An inner member having a raceway surface on the outer surface, an outer member having a raceway surface facing the raceway surface of the inner member on the inner surface and disposed outside the inner member, and the two raceway surfaces A rolling device comprising a rolling element that is freely rollable, wherein at least one of the inner member, the outer member, and the rolling element is the rolling member according to claim 8. A rolling device characterized by that.

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