Study of the Structure Formation during Compression for Selecting Multiaxial Deformation Conditions for an Mg–Ca Alloy

Resumo

The structure homogeneity of the Mg–0.8% Ca alloy is shown to increase with temperature during uniaxial compression. Plastic deformation localizes in narrow and wide deformation bands at 250–350°C. A small number of regions with recrystallized grains is observed only after deformation at 400°C. A relatively homogeneous recrystallized structure with an average grain size of about 20 μm forms after uniaxial compression at t = 450°C. Multiaxial deformation at decreasing temperature in the range 450–250°C significantly refines the initial structure of the Mg–0.8% Ca alloy to an average grain size of 2.1 μm. This structure leads to a significant hardening, namely, an increase in the yield strength to 193 MPa and the tensile strength to 308 MPa. The relative elongation after multiaxial deformation increases by more than two times.