THE EFFECT OF METAL TYPE AND MULTI-LAYERING ON FRICTION SURFACING

Friction surfacing was attempted with a stainless steel, aluminium and brass consumables on a mild-steel substrate in the open air and in fl owing nitrogen. Stainless steel formed a strongly-bonded thick layer b ut friction surfacing with both aluminium and brass was not possible. Both brass and aluminium consumables failed to form a heated layer in contact with the mild steel, high thermal conductivity of either metal being the probable cause of failure to perform friction surfacing. Ni trogen ventilation caused cooling of the heated layer between the stai nless steel and the mild-steel substrate and lowered the quality of th e coating. Multi-layer surfacing by stainless steel consumables was su ccessful, with at least three strongly-bonded layers possible, provide d that the surfaces are free of oily contaminants.