Method of producing a composite material for slide bearings with

Details Method of producing a composite material for slide bearings with Method of producing a composite material for slide bearings with

1997-08-25

1999-09-07

Yoon, Tae

Coating processes

With post-treatment of coating or coating material

Heating or drying

264127, 523149, 524805, C08J 514, B05D 302, C08F 2712

Patent

active

059484799

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The present invention relates to a method of producing a composite material for plain bearings with a plastics overlay, as well as to a paste required in said production. The invention also relates to a method of using the composite material.


BACKGROUND OF THE INVENTION

Self-lubricating be a ring materials are already known. In their most common form they consist of a porous sintered layer of tin or lead-bronze alloys applied to a steel backing. Mixtures of fluoropolymers with various fillers are worked into the porous sintered layer in such a way that they form a layer of from 10 to 30 .mu.m on the sintered backing.
A method for producing self-lubricating bearings is described in DE-PS-1 132 710. In this method a paste produced from a PTFE dispersion (polytetrafluoroethylene dispersion) and fillers is inserted under pressure into cavities in a porous bronze layer and the metal is then sintered. DE-PS-1 132 710 also describes the production of a PTFE filler paste. The fillers are mixed with a PTFE dispersion in a concentration of between 5 and 60%, whereupon, with the aid of a salt which forms an insoluble compound with the dispersion-stabilising ionic wetting agent, coagulation of the PTFE then occurs with homogeneous inclusion of the added fillers. It should be mentioned that in this method volatilizable organic solvents, e.g. toluene, and optionally additionally a surface-active substance, such as ethylphenylpolyglycol ether or a fatty alkyl sulphonate, may be used. The surface-active substances are used for the purpose of better wetting and thus more homogeneous incorporation of the fillers. The organic solvents are used in order to achieve the desired consistency of the paste, which enables the achievement of the necessary small covering layer thicknesses of from 10 to 30 .mu.m on the finished part.
In heavily loaded plain bearings cavities often arise through cavitation, which cavities explode again after a short time, thereby releasing energy. This released energy results in local destruction of the material, whereby the service life of the components made of the material is considerably reduced.


OBJECT OF THE INVENTION

The object of the invention is to provide a method of producing composite materials for plain bearings with a plastics overlay with which defect-free plastics overlays, especially of less than 20 .mu.m may be produced, which exhibit a longer service life and improved cavitation resistance.


SUMMARY OF THE INVENTION

This problem is solved by a method of producing a composite material for plain bearings with a plastics overlay in which a paste free of organic solvents is used.
To produce the paste, a dispersion consisting of up to 60 wt. % fluorothermoplastics with added ionic wetting agent and also water is preferably mixed with from 5 to 50 vol. % of filler, based on the volume of the fluorothermoplastics, with from 0.1 to 1.5 wt. % of a non-ionic wetting agent, based on the amount of fluorothermoplastics, and an excess of water and then precipitated with a precipitation agent, the excess water is removed, the paste is applied to a sintered, porous metal layer covering a backing metal and the multilayer material thus produced is then sintered. The proportion of ionic wetting agent in the dispersion is preferably in the range of from 1 to 5 wt. % based on the amount of fluorothermoplastics.
By using an amount of non-ionic wetting agent specifically conformed to the fluorothermoplastics dispersion used, the release of water by the paste after the precipitation process is slowed down. If the overall concentration of non-ionic wetting agent is kept within a narrow range lying between 0.1 and 1.5 wt. %, preferably 0.1 to 1.0 wt. %, based on the amount of fluorothermoplastics, the paste will reach a state, after coagulation of the fluorothermoplastics and during the stirring process, in which it may be applied to the porous metal backing without defect and in any desired thickness. An alkyl polyglycol ether is preferably used as the non-ionic wetting agent.

REFERENCES:
patent: 4153661 (1979-05-01), Ree et al.
patent: 4615854 (1986-10-01), Pratt et al.
patent: 4732818 (1988-03-01), Pratt et al.
patent: 4740340 (1988-04-01), Pratt et al.
patent: 5019308 (1991-05-01), Pratt et al.
patent: 5312576 (1994-05-01), Swei et al.
Encyclopedia of Chemical Technology, 4th Ed., vol. 11, 1994, pp. 626 and 636.
Kunstoff-Handbuch Bd. XI Carl Hanser Verlag Munchen, 1971, pp. 286-290.

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