抄録
An investigation of amorphous iron-molybdenum alloy films formed by electrodeposition was undertaken to determine the influence of various factors, and the corrosion behavior of the films was also examined. The amount of Fe2+ in the baths influenced whether the iron-molybdenum alloy films were amorphous or crystalline. The amorphous structure was formed by electrodeposition from a bath containing less than about 10wt% Fe2+ when the molybdenum content was 12.5g/L. The presence of Fe3+, however, had a detrimental effect on the electrodeposition of iron-molybdenum alloys. The amorphous structure was formed at a molybdenum content of more than about 20wt% in the electrodeposited films. The relation between the current efficiency and the pH value was observed at a current density of 0.8A/dm2 in a bath containing 12.5g/L of molybdenum and 6.5g/L of iron at 30°C. It was found that film structure changed from crystalline to amorphous with increasing pH value, with a limiting value of 3.7. Electrochemical corrosion tests were curried out in 0.1N H2SO4, 0.1N HCl, 3% NaCl, and 0.5% NaOH aqueous solutions which were air saturated at 25°C. The results indicate that amorphous iron-molybdenum alloy films have higher passivating ability than their crystalline counterparts in all of the solutions studied except NaOH.
