Processing of Amorphous Metal Foils

Abstract

Cutting, bending and bulging of amorphous metal foils were studied to solve the problem of difficulty in shaping them, which prevents the materials from being used widely. The foils mainly used were Ni-based MBF50 and Fe-based 2605S-2 with the thickness of around 25j.lill. The tensile strength, maximum strain and Young's modulus of the foils were measured. Cutting methods studied were high-speed blanking, punch less blanking, blanking by ion implanted punch and die, abrasive water-jet cutting and small diameter nozzle plasma arc cutting. The blanking speed ranging from 0.06 to 15mm/s was used in high-speed blanking experi· ments. The method proved to be effective at large clearance. The newly proposed punchless blanking was realized through the use of plastic sheet and die. The method could cut the foils with high accuracy. Cemented carbide punches are implanted with N+ or B~ ions at L54Me V acceleration voltage. The tool wear of ion implanted tools were smaller than non-implanted tools. Abrasive water-jet cutting could produce cut surfaces without crystallization. The optimum cutting speed depends on the abrasive size and the number of lamina· tions. The size of heat affected zone in small diameter plasma arc cutting was formulated using nozzle-foil distance, arc current, plasma gas pressure and table speed. The bending methods investigated were conven· tional V-bending, L-bending with a lateral force, multi -stage V -bending and V -bending with a soft metaL The bending experiments showed superiority of multi-stage V -bending and V -bending with a soft metal to two others. The bulging experiments using a 2.5mm radius hemispherical punch showed that the conventional bulg· ing was difficult to use on the amorphous metal foils. Applying isostatic back pressure generated by the defor- mation of metals to the foils was very effective in getting the bulged ratio of 0.31.