GB864769A - Improvements in and relating to friction elements for brake and the like mechanisms - Google Patents

Abstract

A friction element for brakes and like mechanisms e.g. disc brakes, drum brakes or clutches comprises a substantially water-and-heat-resistant metal phosphide in a matrix. The phosphide may be of copper, nickel or iron, preferably in the form of angular particles, and the matrix a metal such as copper, iron, brass, bronze, cobalt or nickel, or organic material such as a thermosetting resin, e.g. phenolformaldehyde a melamine-formaldehyde. The phosphide may form 1-7% by weight in 30-99% by weight of metal matrix. Fillers such as inorganic fibrous material e.g. asbestos 20-80%, silica 1-20%, graphite 1-25%, lead 1-20%, molybdenum disulphide 1-20%, manganese 1-40% may also be present. Phosphide in the form of particles passing a 20 mesh screen may be mixed with metal powder, compressed at 3-50 tons/sq. in. and sintered in a reducing or non-oxidizing atmosphere such as carbon doxide, hydrogen, cracked ammonia or cracked coal gas. The element so formed may be then attached to a backing member by rivetting or brazing. Alternatively the powder mixture may be filled into a container forming part of the frixtion cement and sintered therein, sintering temperatures preferably not exceeding 1000 DEG C. Organic bonded phosphides may be formed by wet mixing the ingredients in the presence of an organic solvent, evaporating excess solvent, extruding the mixture and heating to cure the matrix, or by mixing the ingredients dry, compacting in a mould at 1-7 tons/sq. in. and heating to cure the matrix.