Microstructures and mechanical properties of AZ31-0.1Ca magnesium alloy produced by soft-contact electromagnetic casting and hot extrusion

An AZ31-0.1Ca magnesium alloy produced by Soft-contact electromagnetic continuous casting (SEMC) was investigated. The fine homogeneous structure and the precipitated phases were obtained by SEMC. The effects of microalloying of Ca and middle frequency electromagnetic field on AZ31-0.1Ca magnesium alloy were discussed. And the as-cast billets were extruded with different extrusion ratios subsequently. The alloy showed an ultrafine grain size of 2-5 μm due to dynamic recrytallization (DRX) in the course of hot extrusion. The comprehensive properties of the as-extruded alloy are the best at the extrusion ratio of 25, and the hardness, UTS and elongation are 73.9 HB, 356.8~MPa and 16.5%,respectively.