MAGNETIC AMORPHOUS ALLOY MATERIAL HAVING SUPERIOR INSULATING PROPERTY AND CORROSION RESISTANCE

摘要

PURPOSE:To obtain a magnetic amorphous alloy material having satisfactory corrosion resistance and insulating properties, by coatng the surface of an amorphous alloy with a film contg. chromium oxide hydrate and having a specified thickness. CONSTITUTION:A molten alloy consisting of 70-88% in total of Fe, Co and Ni, 7-25% B and the balance Si, P or C or further contg. =5% Cr, Mo, Nb or V is very rapidly cooled on a cooled substrate to obtain a thin amorphous alloy plate. After removing an oxide film from the surface of the plate, the plate is subjected to electrolytic treatment as a cathode in an aqueous soln. contg. chromic acid to form a chromium oxide hydrate film having 0.005-1mum thickness.