Creep of high-strength Mg-Ni-Y-RE alloys

The creep behavior of novel magnesium-base alloys was investigated in the temperature interval between 473 and 623 K. The alloy Mg96Ni3Y1.5CeMM1.5 (wt.%) was produced by two different processing techniques: (i) casting and subsequent hot extrusion at 673 K, and (ii) a casting and powder metallurgy procedure involving cold isostatic pressing of atomized powders and hot extrusion at 673 K. Compressive creep tests with stepwise loading were used for analyses of the creep behavior. The treatment procedure of the alloy does not influence its creep resistance substantially. Detailed analyses of the stress dependences of the creep rate have shown that they can be described by the Garofalo sinh relationship modified for the back stress concept.