Influence of Ni, Cu, Zn and Al additions on glass-forming ability and mechanical properties of Mg-Y-Mm (Mm=mischmetal) alloys

Influence of Ni, Cu, Zn and Al additions on the formation of an amorphous phase in rapidly solidified Mg-Y-Mm alloys, their mechanical properties and thermal stability were the subjects of study in the present paper. The structure of Mg-Y-Mm-(Ni, Cu, Zn or Al) alloys prepared by melt spinning technique has been studied using X-ray diffraction in as-solidified and heat treated state. Their mechanical strength has been examined by using tensile test. The studies showed that quaternary alloys with high mechanical strength and good bending ductility can be produced in Mg-Y-Mm-Ni system. Thermal stability of the amorphous phase and its crystallization in the high-strength Mg-Y-Mm-Ni alloys have been studied using differential scanning calorimetry under continuos heating. Phase composition in fully crystalline state was also determined. Formation of a supercooled liquid and structure relaxation processes precede crystallization of the amorphous phase.