PREPARATION OF EXTERIOR PARTS OF WRIST WATCH

PURPOSE:To obtain the exterior parts of a wrist watch having a complicated configuaation and a fine three-dimensional pattern and excellent in anti-wear property, by a method wherein an ultra-plastic alloy is molded into a predetermined shape in an ultra-plastic state and a titanium nitride layer is formed to the surface of the molded one by ion plating to impact corrosion resistance. CONSTITUTION:An eutectic alloy such as Cu-A or Al-Si is subjected to combined treatment of heat treatment and hot or cold processing to perform the refining of a crystal particle while the obtained ultra-plastic alloy is forged at a temp. for holding an ultra-plastic state to obtain a plate which is, in turn, punched into a predetermined shape by a press to fabricate a wrist watch case having a fine stripe pattern. After this case is washed and degreased, titanium nitride is ion plated to form a golden color hard film. This film has a thickness of about 3mum, does not cover the stripe pattern, has close adhesiveness with a base metal, offsets the deficiency in the corrosion resistance and hardness of the base metal and the excellent case or exterior parts enhanced in anti-wear property can be simply prepared.