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The deformation and fracture characterization of an Mg−2Sn−1Ca alloy were studied through uniaxial isothermal compression tests. The flow stress curves, the efficiency of power dissipation, the instability parameter and the fracture behavior of an Mg−2Sn−1Ca alloy under the condition of various hot working parameters were investigated according to the experimental data. Processing maps were established by superimposing the instability map over the power dissipation map. It was found that flow stress reduces with increases in the deformation temperature and decreases in the strain rate. The processing of Mg−2Sn−1Ca alloys should avoid the instability region in which the conditions are high strain under high temperature and low strain under low temperature. At 473 K or a high strain rate, unidirectional cracks and fish scale cracks can be produced, and cracks can be avoided under the optimum processing area of 623–723 K/0.001–0.1 s−1.

By characterizing the properties of a twin cast-rolled AZ31 sheet after cryogenic rolling, the effects of the initial temperature on the microstructure and mechanical properties of the sheet obtained by cryogenic rolling were studied. The results indicate that the hardness of the alloy was a maximum due to the high-density dislocations in the microstructure when the initial temperature was room temperature. The highest yield strength and elongation appeared at the initial temperature of 200 °C, and the microstructure was mainly fine equiaxed grains. It was observed that fine grains increased, and the yield strength and elongation gradually decreased with the increase of the initial temperature. The overall trend of yield strength and elongation increased first and then decreased. Based on the results of different initial temperature treatments, the optimal microstructure and properties of AZ31 magnesium alloy were acquired when the initial temperature was 200 °C.

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