JPH02274802A - Bonded sintered friction material - Google Patents

Abstract

PURPOSE:To manufacture a joining sintered friction material having excellent wear resistance by bringing a green compact of the specific ratio of Cu, S, C and Fe into contact with a steel material, heating them at the specific temp. under non-oxidizing atmosphere and joining both. CONSTITUTION:The green compact consisting of 5-70 wt. parts Cu, 0.2-3wt. parts (in terms of S) at least one kind selected from group of S, MoS2, WS, FeS, CuS, ZnS, SnS and PbS and <=5 wt. parts C and the balance Fe is brought into contact with steel material, sintered ore or iron green compact. Successive ly, they are heated at 1000-1080 deg.C under the non-oxidizing atmosphere of decom posed ammonia gas atmosphere, etc., and alloy layer containing Cu as the essential component is formed on this contacting boundary part and both are joined. By this method, the joining sintered friction material having excellent strength and wear resistance is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing a bonded sintered friction material with excellent wear resistance.

Conventionally, methods for joining sintered friction members to iron members include:
``Brazing method'' that supplies copper or copper alloy to the bonding surface; ``pressure bonding method'' that applies pressure during heating to force diffusion bonding; and ``pressure bonding method'' that utilizes differences in dimensional changes between multiple bonded objects when heated. There are "shrink fit adhesive method" and "caulking method" which mechanically fixes. However, friction materials manufactured by these methods have drawbacks such as poor adhesion between the friction member and the iron member, high cost, and insufficient wear resistance.

Means for Solving the Problems The present inventor conducted research while taking into account the problems of the above-mentioned prior art, and as a result of the research, the present inventor developed a method for producing iron by applying the reaction of the compounding components contained in the material of the friction member during sintering. It has been found that the drawbacks of the prior art can be substantially eliminated or significantly reduced by bonding the friction member and the iron member by forming an alloy layer at the joining boundary between the members.

That is, the present invention provides the following method: Cu5~
70 parts by weight, SlMoS2, WSSFeS%CuS, Z
A compacted product consisting of 0.2 to 3 parts by weight (total S conversion) of at least one selected from the group consisting of nS, SnS, and PBS, 0.5 parts by weight or less, and the balance Fe is made of steel, sintered iron, or iron press. 1000 to 1 in a non-oxidizing atmosphere when in contact with a powder molded product.
By heating at 080°C, Cu is formed at the contact boundary.
1. A method for manufacturing a bonded sintered friction material, which comprises forming an alloy layer mainly composed of and bonding the two.

In the method of the present invention, Cu, S or an S compound, or graphite is mixed with iron powder in the form of a single primary powder or an alloy powder with Cu S, Fe, etc., and compacted into a predetermined shape. Friction material is used as material for ferrous material (steel, sintered iron,
(powder molded product, etc.). This is heated to 1000 in a non-oxidizing atmosphere such as a decomposed ammonia gas atmosphere.
When heated at ~1080° C., S in the ingredients of the friction member material is alloyed with Fe, Cu, etc. forming the base material, and a liquid phase mainly composed of Cu is formed. At the contact boundary, S selectively diffuses from this liquid phase into the mating steel base, the melting point of the liquid phase rises, and it solidifies. The above reaction is repeated to form an alloy layer mainly composed of Cu at the boundary, and the two members are bonded together.

Cu is an essential component of the friction member material, and is alloyed by sintering to join the friction member and the iron member. Cu is in the form of a single powder or an alloy powder with Fe and/or S, and when the total raw material powder weight of the friction member material is 100 parts by weight, 5
~70 parts by weight is used. If it is less than 5 parts by weight, the amount of liquid phase is insufficient and no alloy layer is formed, and if it exceeds 70 parts by weight, the amount of liquid phase becomes too large and the friction material cannot be maintained in a predetermined shape.

S has a particularly strong affinity for Fe and is an essential component for alloying. S is single powder, MoS2, WSSFe
d, Cub, ZnS.

The S compounds of SnS and PbS are used in the form of powder in an amount of about 0.2 to 3 parts by weight in terms of Sn.

These S powders and S compound powders can be used alone or in combination of two or more. If the blending amount is less than 0.2 parts by weight, the amount of liquid phase will be insufficient and an alloy layer will not be formed, and if it exceeds 3 parts by weight, the amount supplied will be excessive than the amount of diffusion at the boundary. , alloy layer is difficult to form.

Although C is not a component that contributes to bonding, it is alloyed with the mating steel base to increase the strength and wear resistance of the friction material, and remains as graphite in the sintered friction member base to stabilize friction performance. C is used as graphite powder in an amount of about 5 parts by weight or less. If it exceeds 5 parts by weight, the strength and abrasion resistance will warp and deteriorate.

The blending amount of C is more preferably about 0.5 to 5 parts by weight.

Fe is an essential component and forms the base of the friction member, improves the strength of the member, and is further alloyed by sintering to provide bonding with the iron member. Fe is preferably reduced Fe.
powder is used, and the above-mentioned Cu.

It is blended in a total amount of 100 parts by weight together with the S and C components.

In the present invention, if necessary, other components that have a relatively strong affinity for Fe, contribute to the formation of an alloy layer, and can improve the wear resistance, friction performance, etc. of the friction material are blended into the friction member material. can do. Such a component is 5nS
Sn compound, Zn.

Examples include one or more of Zn compounds, pb, pb compounds, p, p compounds, and the like. The blending amount is Cu5S, C
and when the total amount of Fe components is 100 parts by weight, approximately 2
It is 8 parts by weight or less. When Cuff1 is 100 parts by weight, the blending amount is about 10 parts by weight or less as Sn, about 30 parts by weight or less as Zn, about 30 parts by weight or less as Pb,
The amount of P should not exceed about 2 parts by weight, and the total amount should not exceed 40 parts by weight. If the amount exceeds the above, the amount of liquid phase increases, making it impossible to maintain the ζ friction material in a predetermined shape.

In the present invention, the raw material powder of such a friction member material is preferably adjusted to a particle size of 74 to 147 μm or less. If necessary, a known molding lubricant such as zinc stearate powder may be added.

The molding method, molding conditions, etc. are not particularly limited, and known methods can be used as they are.

The material of the iron member to be joined may be steel, sintered iron, or iron compacted product manufactured by a conventional method, and the composition, manufacturing conditions, etc. thereof are not particularly limited.

In the present invention, the friction member material and the iron member material are brought into contact and sintered by heating in a non-oxidizing atmosphere such as decomposed ammonia gas or propane modified gas in a range of 1000 to 1080°C.

Below 1000°C, the amount of liquid phase of the molten metal is small;
The alloy layer is insufficiently formed at the boundary, and when the temperature exceeds 1080° C., Cu melts, making it impossible to form a good alloy layer.

The friction material of the present invention can be applied in cases where both frictional properties and strength properties are required, and in cases where various shapes are combined to create products with complex shapes.

Effects of the Invention The method of the present invention can be carried out at low cost without using any special equipment. The sintered friction material manufactured is
Since the friction member and the iron member have good bonding properties, it has excellent strength, wear resistance, etc.

EXAMPLES Below, examples and comparative examples of the present invention will be shown to explain the present invention.

Example 1 15 parts by weight of atomized Cu powder with a particle size of 74 μm or less, particle size 147
1 part by weight of S powder with a particle size of 74 μm or less and 1 part by weight of natural graphite with a particle size of 74 μm or less are reduced to mill scale F with a particle size of 147 μm or less
It was blended into powder e so that the total amount was 100 parts by weight. Furthermore, 1 part of zinc stearate powder was added to this mixture as a mold lubricant.
After adding the weight parts and mixing uniformly, the specific gravity is 6.6 and the outer diameter is 4.
Compression molding was carried out into a shape of 0.61×inner diameter 32 mm×10+n to obtain a powder-molded friction member material.

2 parts by weight of atomized Cu powder with a particle size of 74 μm or less is mixed with a particle size of 147 μm.
Mixed with 98 parts by weight of atomized Fe powder of less than Compression molding was carried out into a shape with an inner diameter of 40.7 mm x 10 m to obtain a steel member material.

The above-mentioned friction member material was incorporated inside the iron member material obtained above, and this was heated at 1070°C for 15 minutes in an atmosphere of decomposed ammonia gas in an electric furnace, and then sent to a water cooling jacket and cooled. A friction material (a) was obtained.

Example 2 15 parts by weight of atomized Cu powder with particle size of 74 μm or less, particle size of 74 μm
1 part by weight of stamped Sn powder with a particle size of 147 μm or less, 2 parts by weight of MoS 2 powder with a particle size of 74 μm or less, and a 0.8 mold part of natural graphite with a particle size of 74 μm or less were combined into mill scale reduced Fe powder with a particle size of 147 μm or less. It was blended so that it was 100 parts by weight. Furthermore, 1 part by weight of zinc stearate powder was added as a mold lubricant to this mixture, and after uniformly mixing, the specific gravity was 6.6.
Compression molding was carried out into a shape with an outer diameter of 40.6 mm, an inner diameter of 32 mm, a width of 10 sn, and a powder-molded friction member was obtained.

A mixture of 2 parts by weight of Cu, 4 parts by weight of Ni, and 94 parts by weight of Fe was sintered at 1150°C for 30 minutes in a decomposed ammonia gas atmosphere to produce a product with a specific gravity of 7.1 and an outer diameter of 60 m5 + x inner diameter of 4.
0. An iron member material having a shape of 7++ueX 10+u was obtained.

The above-mentioned friction member material was incorporated inside the iron member material obtained above, and this was heated at 1020°C for 15 minutes in an atmosphere of decomposed ammonia gas in an electric furnace, and then sent to a water cooling jacket and cooled. A friction material (b) was obtained.

Comparative Example 1 A comparative friction material (c) was produced in the same manner as in Example 1 except that the amount of Cu powder used as the raw material for the friction member material was 3 parts by weight.

Comparative Example 2 A comparative friction material (d) was produced in the same manner as in Example 1 except that the sintering temperature was 1100°C.

Test Example 1 The iron member side of the friction materials (a) to (d) obtained in Examples 1 and 2 and Comparative Examples 1 and 2 above was fixed to a jig, and the iron member side was fixed in the thickness direction near the boundary line on the friction member side. A load was applied and the shear strength was measured (sample dimensions: thickness 5 mm x width 10 mm x length (
10) mm). The measurement results are shown in the table below.

The fractured surface is gray, but the friction materials (a) and (b) of the present invention
The boundary fracture surface was copper-colored, and it was clear that an alloy layer mainly composed of copper had been formed.

Further, FIG. 1 shows cross-sectional micrographs (x 200) of the friction materials (a) and (d). From this figure, it is clear that in the friction material of the present invention, an alloy layer is formed by penetrating into the pores of the contact boundary.

[Brief explanation of drawings]

FIG. 1 shows a cross-sectional micrograph of the friction material (a) obtained in Example 1 and a cross-sectional micrograph of the friction material (d) obtained in Comparative Example 2. (Above) Observation of the boundary fracture surfaces of Friction 1 (a) to (d) above revealed that Comparative Friction Materials (C) and (d) Boundary Procedure Amendment Document 1 Case Indication 1999 Patent Application No. No. 97725 2 Name of the invention Nippon Powder Alloy Co., Ltd. 4 Agent Sawanotsuru Building, 2-1-2 Hirano-cho, Chuo-ku, Osaka July 25, 1999 6 "Brief explanation of the drawings" in the specification subject to amendment Contents of amendment 1: “Cross section” in page 12, line 11 and line 12 of the specification
``Indicates the metal structure of the alloy layer.''(that's all)

Claims (1)

[Claims] (1) Cu5-70 parts by weight, S, MoS_2, WS, F
A compacted product consisting of 0.2 to 3 parts by weight (in terms of S amount) of at least one selected from the group consisting of eS, CuS, ZnS, SnS, and PbS, 5 parts by weight or less of C, and the balance Fe is made into steel and sintered. By bringing it into contact with iron or an iron compacted product and heating it at 1000 to 1080°C in a non-oxidizing atmosphere, an alloy layer mainly composed of Cu is formed at the contact boundary,
A method for producing a bonded sintered friction material, which comprises bonding both.