PREPARATION AND STRUCTURES OF AMORPHOUS NI-CO-B ALLOY-FILMS ELECTRODEPOSITED ON ROTARY ELECTRODE

The authors have studied the preparation of amorphous Ni-Co-B alloy films to be electrodeposited with a rotary electrode, in comparison to the conventional static bath method. The structures of such films have been also studied, and the following conclusions are obtained. Using the rotary electrode, amorphous alloy films can be prepared with a formation range approximately 10 times wider than the extremely narrow range allowed by the conventional static bath method. The optimum peripheral speed of the cathode is 70 cm/s for the preparation of amorphous alloy films by means of the rotary electrode. The content of hydrogen in such a film becomes higher than that prepared by the static bath method. Alloying of the hydrogen appears to be related with the non-crystallization or formation of finer crystal grains in the film, in comparison to the static bath method. Intermetallic compound CoB is formed between the substrate and the amorphous alloy film.