AMORPHOUS ALLOY FOIL IMPROVED IN CRYSTALLIZATION RESISTANCE IN SURFACE LAYER AND ITS PRODUCTION

摘要

PURPOSE:To form an Sn segregation layer in the surface and to improve magnetic properties, corrosion resistance, and thermal stability by rapidly cooling an alloy having a composition where Sn is incorporated into the essential components of the prescribed composition and then subjecting the resulting amorphous alloy foil to ageing treatment under the prescribed conditions. CONSTITUTION:An alloy having a composition in which MaXbSicBdCe [where M means Fe, Co, and Ni, X means Mo, Nb, Ta, W, Cr, V, Mn, and Cu, the symbols (a), (b), (c), (d), and (e) stand for, by atomic%, 60-90, 0-6, 1-19, 7-20, and 0-4, respectively and (a+b+c+d+e)100] is contained as essential components and Sn added by 0.01-1wt.% to the above components is refined. Subsequently, this alloy is cooled rapidly by a one side cooling method, by which an morphous alloy foil is prepared. Then, this foil is held at 100-300 deg.C for 0.5-1000hr, by which an Sn concentration segregation layer having =0.03mum thickness and a peak value =5 times the bark is formed in the surface layer, and crystallization resistance can be increased.