METHOD FOR FORMING SELF-LUBRICATING ANODIC OXIDIZED FILM OF ALUMINUM AND ITS ALLOY

摘要

PURPOSE:To easily form a self-lubricating anodic oxidized film by accumulating a sulfur compound in a chemical forming film by performing the current reversal electrolysis of an Al-material in a sulfuric acid electrolyte and subsequently immersing the treated Al-material in a metal salt solution. CONSTITUTION:Al or an Al-alloy is subjected to current reversal electrolysis in sulfuric acid or an electrolyte containing sulfuric acid in such a state that polarity is cyclically changed and the chemical forming of a film is cyclycally interrupted. By this method, the electrolyte is reduced by a negative current simultaneously with the chemical forming of the film to form and accumulate a sulfur compound in the film. Subsequently, the treated one is treated with a lubricating metal salt solution containing metal salts such as a Zn-salt or an Mo-salt while the treated one is further subjected to pore sealing treatment to contain and fix metal sulfide having lubricating property in the film. By this method, a self- lubricating anodic oxidized film can be formed on the Al-material in a simple process.