Summary: | Hot extrusion is employed to fabricate an AZ31-Nd magnesium alloy adopting AZ31 chips and Mg-Nd intermediate alloy chips. The microstructure evolution and mechanical properties after different extrusion passes are studied, as well as the effect of solution and aging treatment on the mechanical properties of AZ31-Nd magnesium alloy. The results show that hot extrusion is fit for breaking up the intermediate alloy chips into fine and dispersive particles. These particles have an effect on a higher nucleation rate and a greater strength of the alloy together with fine oxide phases, which are subjected to fine-grain strengthening and dispersion strengthening. After four extrusion passes, the tensile strength reaches 313 MPa, and the elongation reaches 12.01%. The fracture is composed of cleavage planes, tear ridges and dimples. After solution and aging treatment, a large amount of the Al2Nd phases are precipitated. The precipitation of these phases imporves the tensile strength and elongation of AZ31-Nd alloy. Keywords: Hot extrusion, Rare earth magnesium alloy, Microstructure, Mechanical propertiy, Heat treatment
|