JPH04224884A - Composite rotor disc - Google Patents

Abstract

PURPOSE:To provide a lightweight rotor disc which is excellent in corrosion resistance, etc., and can remedy the deficiency of conventional rotor discs made of iron. CONSTITUTION:A rotor disc obtained by putting together a disc body made of iron, aluminum or titanium and a ceramic friction member made by sintering a composite material consisting of an alumina or silicon nitride matrix having a purity of 99% or higher and a particle size of 1mum or smaller and silicon carbide or silicon nitride whiskers dispersed therein to a sinter density of 98.5% or higher. It is very lightweight with high strength and excellent in frictional performance and abrasion resistance. It is so hard that it is difficultly marred and is excellent in corrosion resistance and durability. In addition, it is a highly reliable material with high strength, toughness and heat resistance. Therefore, it is effective in reducing the weight of an automobile disc brake mechanism.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite rotor disk, and more particularly to a composite rotor disk that is lightweight, has high strength, has excellent durability, and is effective in reducing the weight of rotor disks in automobile disc brake mechanisms and the like.

0002

2. Description of the Related Art Conventionally, rotor disks for automobiles have been mainly made of iron because of their low cost, high reliability of materials, and ease of manufacture.

[0003] Nowadays, from the perspective of global environmental conservation,
In the automobile-related field, there is also a movement towards energy conservation, and as a countermeasure to this, reducing the weight of automobiles has become a major issue. Therefore, it is desired that the weight of the rotor disk be reduced as well.

0004

[Problems to be Solved by the Invention] Conventional steel rotor disks for automobiles are heavy. ■Easy to rust. There are drawbacks such as (2), which has a large effect on the fuel efficiency, acceleration, and inertia of the automobile, and (2), which causes rust, which is a drawback to the braking force and braking mechanism, and goes against energy conservation.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and provide a composite rotor disk that is lightweight, has high strength, and has excellent durability.

[0006]

[Means for Solving the Problems] The composite rotor disk of the present invention is a composite rotor disk in which a ceramic friction member is adhered or bonded to a metal disk body, and the metal disk body includes: A ceramic friction member made of one metal or an alloy of two or more selected from the group consisting of iron, aluminum, and titanium,
A composite ceramic material of a matrix powder made of alumina or silicon nitride and dispersed whiskers made of silicon carbide or silicon nitride is sintered to a sintered density of 98.5% or more, the matrix powder has a purity of 99% or more, Particle size 1
The ceramic friction member is characterized in that it is a powder of micrometer or less and the proportion of dispersed whiskers is 5 to 40% by weight of the composite ceramic material.

The present invention will be explained in detail below. The metal disk body of the composite rotor disk of the present invention is made of one or more alloys selected from the group consisting of iron, aluminum, and titanium. If the thickness of such a metal disk body is too thin, the strength will be insufficient, and if it is too thick, the weight will increase, which is not preferable. Therefore, the thickness is set to about 1/2 to 1/3 of the total thickness of the rotor disk, specifically about 3 to 5 mm, particularly about 2.5 to 4 mm.

On the other hand, the ceramic friction member of the composite rotor disk of the present invention is made of alumina (Al2O3
) or silicon nitride (Si3N4) as the matrix powder, and silicon carbide (SiC) whiskers or silicon nitride (Si3N4) as the matrix powder.
3N4) It is manufactured by sintering a composite ceramic material having dispersed whiskers.

In the present invention, the proportion of dispersed whiskers in such a composite ceramic material is 5 to 40% by weight. If this proportion is less than 5% by weight, the improvement effect due to the use of dispersed whiskers cannot be sufficiently obtained. vice versa,
If it exceeds 40% by weight, moldability and strength will be impaired. Therefore, the proportion of dispersed whiskers is between 5 and 40% by weight.

[0010] The diameter and length of the dispersion whiskers to be used are not particularly limited, but in general, diameters of 5 μm or less and lengths of 50 μm or less are preferred.

[0011] Such a composite ceramic material can be prepared by thoroughly mixing matrix powder and dispersed whiskers of a desired composition using a ball mill or the like.

The matrix powder constituting these composite ceramic materials used as a sintering raw material has a particle size of 1 μm.
It is required to be a high-purity fine ceramic powder with the following fine particles and a purity of 99% or more.

The ceramic friction member according to the present invention includes:
Such a sintered raw material composite ceramic material, for example,
Formed into a disk using a press method, wet suction press method, or CIP (hydrostatic press) method, and a sintered density (relative density) of 98.5% or more using a firing method suitable for each raw material ceramic.
It can be easily manufactured by firing to Here, there is no particular restriction on the firing method, and pressureless sintering, atmosphere sintering, HP (hot press), HIP (hot isostatic pressing) methods, etc. can be employed.

[0014] By bonding or joining the ceramic friction member manufactured in this way and the metal disk body by brazing, diffusion bonding, etc.,
The composite rotor disk of the present invention can be easily manufactured.

[0015]

[Operation] The composite rotor disk of the present invention is made by integrating a metal disk body and a ceramic friction member, and has the excellent properties of both metal and ceramics. Among the constituent metals of the metal disk body, iron has excellent strength and heat resistance, but has the disadvantage of being heavy. On the other hand, aluminum and titanium are lightweight, but have problems with friction characteristics and heat resistance. On the other hand, ceramic sintered bodies are lighter than iron, have excellent corrosion resistance, high wear resistance, and high hardness. In particular, ceramic sintered bodies with alumina or silicon nitride as a matrix and dispersed with silicon carbide whiskers or silicon nitride whiskers have all the characteristics such as light weight, high strength, high toughness, high heat resistance, and high corrosion resistance due to the reinforcing action of the whiskers. Required characteristics are satisfied. Moreover, the sintered body obtained by sintering the high-purity ceramic fine powder and whiskers used in the present invention at high density is extremely excellent in all properties such as light weight, high strength, and rust resistance. That is, since the material has a high purity of 99% or more, the excellent characteristics of the material can be fully exhibited. In addition, since it is a fine powder with a particle size of 1 μm or less, high-density sintering is possible, and since it is a high-density sintered body with a sintered density of 98.5% or more, it has excellent strength, hardness, wear resistance, and friction performance. It has extremely excellent mechanical properties such as and corrosion resistance.

In the composite rotor disk of the present invention, since the ceramic friction member is integrated with the metal disk body, the heat resistance and frictional properties of the friction surface are ensured by the ceramic friction member, and the ceramic friction member is lightweight. At the same time, the metal disk body ensures mechanical properties such as impact resistance and toughness that ceramics lack.

According to the composite rotor disk of the present invention, (1) it is lighter than the conventional iron rotor disk; ■Because it does not rust like conventional iron rotor disks,
No problems with the braking mechanism. ■Compared to iron rotor disks, the rotor surface has greater hardness, and the rotor will not be scratched by deposits or other debris. ■Less affected by the material on the disc pad side. ■ High toughness,
It has high heat resistance and can withstand rapid temperature rises. ■ Excellent impact resistance and high strength. The following effects are achieved.

[0018]

[Examples] The present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

Examples 1 to 6, Comparative Example 1 The composite ceramic raw materials shown in Table 1 were prepared by mixing each raw material in a ball mill for 20 to 200 hours. Using this composite ceramic raw material, mechanical press or CI
It was formed into a disk shape using P and then sintered, with a diameter of 200 mm.
A ceramic friction member with a thickness of 6 mm was manufactured. In addition,
Press pressure is 500-1500kg/cm2, CIP
The molding pressure is 1000-1500 kg/cm2, and the sintering is performed at the optimum temperature for each composite ceramic powder (1600-190 kg/cm2).
0℃), and the relative density by sintering (1800℃) was 98
．． It was set at 5% or more. All the powders used had a purity of 99% or more and a particle size of 1 μm or less, and the whiskers had a diameter of 5
The length is 50 μm or less.

Separately, a diameter 20 mm made of the metal shown in Table 1
A metal disk body having a diameter of 0 mm and a thickness of 4 mm was manufactured, and the friction member was bonded to the disk body by brazing or diffusion bonding to be integrated. The obtained rotor disk was subjected to a performance test and compared with a conventional iron rotor disk (Comparative Example 1). The results are shown in Table 1.

[0021]

[Table 1]

[0022] From Table 1, the composite rotor disk of the present invention has a coefficient of friction that is almost as good as that of the conventional iron rotor disk, has good wear resistance, and has high hardness. It is clear that the rotor disk is significantly superior to iron rotor disks in terms of scratch resistance and durability, and is also extremely lightweight, with a weight reduction of 30 to 50% compared to conventional iron rotor disks. It is also clear that the fracture toughness value is large and the reliability of the material is also high.

[0023]

[Effects of the Invention] As detailed above, the composite rotor disk of the present invention has excellent friction performance, wear resistance, mechanical strength, corrosion resistance, durability, heat resistance, impact resistance, and material reliability. A rotor disk having excellent hardness, high toughness, and extremely light weight is provided. The composite rotor disk of the present invention can be used in disc brake mechanisms for automobiles, etc. to reduce the weight thereof, and is extremely useful industrially.

Claims (1)

[Claims] 1. A composite rotor disk comprising a metal disk body and a ceramic friction member adhered or bonded, wherein the metal disk body is made of one type selected from the group consisting of iron, aluminum, and titanium. The ceramic friction member is made of a composite ceramic material of a matrix powder of alumina or silicon nitride and dispersed whiskers of silicon carbide or silicon nitride, and has a sintered density of 98. 5% or more, the matrix powder is a powder with a purity of 99% or more and a particle size of 1 μm or less, and the proportion of dispersed whiskers is 5 to 40% by weight of the composite ceramic material. A composite rotor disc characterized by: