Eiji Tsunasawa

Process parameters and some properties of ion‐plated titanium coatings on steel substrates

The effects of process parameters on the formation of the titanium films were studied and some properties of the coatings (such as hardness, morphology, porosity, corrosion resistance, and adhesion) were examined. The titanium coatings deposited on steel substrates were prepared by ion‐plating techniques using a diode system with electron‐beam heating of the source materials. Knoop hardness of ion‐plated titanium coatings formed for 3 min at negative bias of 3 kV, process pressure of 1.3×10−3 Pa, and substrate temperature of 150°C, showed higher values as compared with the value of an annealed pure titanium sheet. The porosity of these coating was considerably affected by the coating thickness. The titanium coatings above 5 μm of the thickness indicated a satisfactory corrosion resistance in 3%‐NaCl aqueous solution. The ion‐plated titanium coatings showed better adhesion to steel substrates than coatings obtained by conventional vacuum vapor deposition.