Microstructures and Creep Properties of Mg-2.5Zn-xCe (x = 4,6 and 8 mass%) Alloys

摘要

The effect of 4,6 and 8 (mass%) Ce additions on the microstructure and creep resistance of the Mg-2.5Zn alloy was investigated by tensile creep test in the temperature of 200 ℃, 225℃ with the tensile stress of 60 MPa and tensile test in room temperature. The microstructure and phase composition of these alloys were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD). The results showed that the grain sizes of Mg-2.5Zn-xCe alloys were decreased and the creep strength of the base alloy was remarkably improved by increasing Ce addition. This were attributed to the formation of Mg_12Ce, Mg_2Ce and (Mg,Zn)_12Ce compounds that morphology remains relatively stable at moderately elevated temperature which strengthen both matrix and grain boundaries during creep deformation.