CRYSTALLIZATION BEHAVIOR OF A BULK AMORPHOUS MG62CU26Y12 ALLOY

The crystallization temperature, the associated activation energy and the crystallized structure of a bulk amorphous Mg62Cu26Y12 alloy with a diameter of 2.5 mm were studied. It possesses a one-step crystalliza tion behavior. The crystallization reaction was found to be represente d by: AM(MG62Cu26Y12)-->Mg2Cu + MgY + CuY + Mg, (T(x) = 188-degrees-C, E(ac) = 134 kJ/mol) where AM represents the amorphous state, T(x) the crystallization temperature at an infinitesimal heating rate, and E(a c) the associated activation energy. The amount of crystalline phases were found to be Mg2Cu:MgY:CuY = 76:17:7. The Mg phase is identifiable only by high resolution electron microscopy, not by X-ray diffraction . The crystallization leads to a sharp rise in electrical resistivity which is reversed to those of iron-based amorphous alloys.