Research on deformation mechanism of AZ31 magnesium alloy sheet with non-basal texture during uniaxial tension at room temperature:A visco-plastic self-consistent analysis

摘要

The relationship between activities of involved deformation mechanisms and the evolution of microstructure and texture during uniaxial tension of AZ31 magnesium alloy with a rare non-basal texture has been thoroughly investigated in the present study by means of electron backscattered diffraction(EBSD)measurement and visco-plastic self-consistent(VPSC)modeling.These results show that except basalslip and prismaticslip,{10■2}extension twin(ET)also plays a significant role during plastic deformation.With the increasing tilted angle between loading direction and rolling direction(RD)of sheet,the activity of{10■2}ET possesses a decreasing tendency and its role in plastic deformation changes from the one mainly sustaining plastic strain to the one mainly accommodating local strain between individual grains.When{10■2}ET serves as a carrier of plastic strain,it mainly results in the formation of basal texture component(c-axis//ND,normal direction).By comparison,when the role of{10■2}ET is to accommodate local strain,it mainly brings about the formation of prismatic texture component(c-axis//TD,transverse direction).At large plastic deformation,the competition between basalslip and pyramidalslip is responsible for the concentration of tilted basal poles towards ND within all deformed samples.The larger difference is between the activities of basalslip and pyramidalslip,the smaller separation is between these two tilted basal poles.Besides,VPSC modeling overestimates volume fractions of{10■2}ET in samples with angle of 0 to 30°between loading direction and RD of sheet because interactions between twin variants are not included in VPSC modeling procedure at the present form.In addition,as compatible deformation between individual grains cannot be considered in VPSC modeling,the predicted volume fractions of{10■2}ET in samples with angle of 45 to 90°between loading direction and RD of sheet are smaller than the correspondingly measured results.