SURFACE TREATMENT OF THIN AMORPHOUS MAGNETIC METALLIC STRIP

摘要

PURPOSE:To prevent the deterioration in magnetic characteristic owing to a surface treating film by spraying a molten metal onto a cooling body under high-speed rotation to form a thin amorphous magnetic metallic film and spraying a surface treating agent to the surface thereof immediately after such formation. CONSTITUTION:The molten metal M which is an Fe magnetic alloy in a crucible 3 is sprayed from a nozzle 5 onto a rotary roll 1 made of a copper alloy having excellent heat conductivity while said roll 1 is rotated at a high speed to form the thin strip of the amorphous alloy by quick cooling on the roll surface. The pulverous powder C of alumina as the surface treating agent in a spraying device 11 is atmized onto the surface of the thin amorphous magnetic metallic strip from a nozzle 12 right after said formation to form the thin film of the surface treating agent. The coefft. of the thermal expansion of the thin film by the surface treating agent is extremely smaller than the coefft. of themal expansion of the thin amorphous magnetic metallic strip and therefore the residual tensile strain is generated in the thin metallic strip as a result of a difference in the coefft. of thermal expansion in the cooling stage of the thin strip and the thin film, by which the deterioration of the magnetic characteristic of the thin amorphous magnetic metallic strip is obviated and said characteristic is rather improved.