This specification establishes the engineering requirements for producing a hard aluminum oxide coating, impregnated or codeposited with polytetrafluoroethylene (PTFE) on aluminum alloys.This process has been used typically to increase, by the formation of a dense, PTFE-impregnated aluminum oxide or codeposited PTFE-aluminum oxide layer, surface hardness and resistance to abrasion and corrosion of alloy parts containing, in general, less than 5% copper or 8% silicon or a total of 8% of both.