Influence Of Deformation Conditions On Dynamic Recrystallization And Twinning Characteristics Of Magnesium Alloy

Nowadays magnesium alloy is the lightest metallic structure material withhigh specific strength, high damping, good electromagnetic shielding, dimensionalstability and recyclability, etc. These advantages promote magnesium alloys with a widerange of applications prospects in the aerospace, automotive and a variety of consumerelectronics products. However, the poor cold plastic forming and higher production costslead to a limited application of magnesium alloy. Therefore, it is necessary to conductfurther research on deformation mechanism of magnesium alloy.Although right now more than90%of magnesium alloy structural components areproduced by die-casting process, wrought magnesium parts with fine grain size,homogeneous, and less defects are more and more appealing to the researchers andcompanies. With computer-aided hot forging simulator(Thermec-master Z) and EBSDorientation angle analysis, the microstructure and texture evolution of magnesium alloywere investigated by combination of various deformation temperature and strain rate,especially focused on the deformation mechanism with different deformation conditions.In addition, in this paper, tensile twins generated with different strain rate in hotdeformation were investigated in details and how these tensile twins influenced dynamicrecrystallizaition and texture evolution at different strain rate.The original stress-strain curves with different deformation conditions can beobtained via hot compression test. After friction correction and temperature correction,these curves can be used to construct the processing map which can be used to predict theoptimum forging condition and unstable processing area. In addition, the value ofactivation energy Q was calculated at various hot deformation condition with the help ofmaterial constitutive equation and the Q value distribution contour map has been draw out.Finally, with the help of simulation, the influence of inhomogeneous deformationwhich is induced by friction and heating was investigated in details. The optimumobservation spot which can be consistent with deformation condition was indicated. Afterthat, inhomogeneity in microstructure and texture was verified by EBSD testing.