Method of applying hard-facing materials

Abstract

Abstract Method for applying hard-facing materials to metal substrates through the use of a composite mat consisting of a laminate of two sheets of pliable material. Each of the sheets contains a network of polytetrafluoroethylene fibers which are biaxially oriented. One of the sheets contains particles of a hard-facing material while the other contains particles of a brazing alloy. The laminated sheets are applied to the surface and then the resulting assembly is heated to a brazing temperature whereupon the polytetrafluoroethylene is volatilized and the brazing alloy is melted, producing a dispersion of the hard-facing material particles in a matrix of brazing alloy securely bonded to the substrate. The sheets are prepared by making a slurry of polytetrafluoroethylene particles and hard-facing particles or brazing alloy particles, as the case may be, in combination with a volatile liquid vehicle. After draining off excess vehicle, the resulting limp sheet is subjected to a rolling pressure in two mutually perpendicular directions to thereby fibrillate the resin particles to produce a biaxially oriented network of polytetrafluoroethylene fibers in which the metallic particles are dispersed. A sheet containing the hard-facing particles is then laminated to a similar sheet containing brazing particles. The resulting laminate is then cut to size and applied to the surface of the substrate.

Inventors

• 👤 Frank T Lally

Bibliographic Details