Effect of Cold Rolling on the Physical Properties and the Structure of Fe₇₉B₁₆Si₅ Amorphous Alloy

Abstract

The effect of cold rolling on the physical properties and the structure of Fe₇₉B₁₆Si₅ ribbon amorphous alloy was investigated by Mössbauer effect, X-ray diffraction, tensile test and electrical resistivity measurements. The shape of the distribution of the internal magnetic field was hardly affected by cold rolling, but the peak in the distribution, (H_peak), shifted only slightly to the low field side. It seems that cold rolling causes the decrease of the component of magnetization parallel to the ribbon plane of the specimen. A large softening effect by about 5% cold rolling and a hardening effect by subsequent rolling were observed in the amorphous alloy. This hardening trends to increase toward that in the as-quenched state. Increase of the average Fe-Fe atomic distance would be responsible for the softening. It is suggested that the hardening is probably caused by strain hardening associated with subsequent rolling. From the topological point of view, it is likely that cold rolling produced a more disordered structure than that present in the as-quenched state. The thermal stability of the amorphous structure was not improved by cold rolling.