Metal-plastic composite bearing material - has metal backing, middle layer of porous sintered metal and sliding layer of PTFE contg. finely-dispersed co-polyimide particles

摘要

A metal-plastic composite bearing material (I) has a metal backing (A), esp. of steel or copper-plated steel, coated with a porous layer of sintered metal (B) and a sliding layer (C) consisting of a PTFE matrix contg. a polymeric additive. The additive contains finely-dispersed copolyimide(s) (II) in amts. of 10-40 wt.% w.r.t. the PTFE. USE/ADVANTAGE - (I) is a dry bearing material with a low coefft. of friction and with wear resistance and cavitation resistance at least no worse than those of prior-art materials (esp. e.g. those with sliding layers contg. PTFE with other additives); addn. of (II) makes the material less brittle without increasing the coefft. of friction or lowering the thermal stability, so that the prodn. reject rate is lower. The material is not difficult to process and is suitable for use under complex operating conditions, esp. high running speeds and high specific loads, as required in motor vehicles, etc.