Effect of deformation conditions on microstructure and texture during compression of Mg-3Sn-2Ca-0.4Al-0.4Si alloy

Micro-alloying elements (0.4% Al and 0.4% Si) were added for the purpose of texture weakening and thereby to improve formability of cast Mg-3Sn-2Ca (TX32) alloy. Hot deformation behavior was studied by conducting isothermal uniaxial compression tests at temperature from 300 to 500 °C and strain rates in the range 0.0003-10 s-1. Optical microscopy studies revealed the occurrence of dynamic recrystallization (DRX) at certain deformation conditions and the texture was characterized by electron backscatter diffraction (EBSD) technique in scanning electron microscope. The plastic deformation is controlled primarily by slip during deformation. The texture component varied depending on deformation conditions; the basal poles are spread out from the compression axis and the (0001) slip is predominating as DRX grains have high Schmid factor distribution for basal slip at lower temperatures (300, 350 oC) and lower strain rates (0.0003, 0.001 s-1). Average recrystallized grain size increased with increase in temperature and the mechanisms of texture evolution changed significantly from 400 oC due to activation of additional slip modes and resulted in more randomized texture at higher temperatures and high strain rates.