Rapid-cooling friction-stir-welding(FSW)was used to join AZ31B magnesium alloy plates of 6 mm in thickness.The microstructure and mechanical properties in thickness direction were carefully investigated with electron ...Rapid-cooling friction-stir-welding(FSW)was used to join AZ31B magnesium alloy plates of 6 mm in thickness.The microstructure and mechanical properties in thickness direction were carefully investigated with electron backscattered diffractometer,and transmission electron microscope.The obtained results showed that ultrafine grains with high dislocation density were obtained in the top region of the weld due to liquid CO2 cooling.A large number of{1012}twins and second-phase particles were also induced in these refined grains.The basal texture intensity was significantly reduced due to the appearance of{1012}twins.The top region showed the higher strength and elongation compared with the bottom region,and the welding efficiency reached 93%.This work provided a simple and efficient strategy for manufacturing a gradient structure in the FSW Mg alloy joint.展开更多
基金Project(51805145)supported by the National Natural Science Foundation of ChinaProject(CJ20200076)supported by the Changzhou Science and Technology Program,China+1 种基金Project(B200202229)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(2020102941517)supported by Hohai University Undergraduate Innovation and Entrepreneurship Training Program,China。
文摘Rapid-cooling friction-stir-welding(FSW)was used to join AZ31B magnesium alloy plates of 6 mm in thickness.The microstructure and mechanical properties in thickness direction were carefully investigated with electron backscattered diffractometer,and transmission electron microscope.The obtained results showed that ultrafine grains with high dislocation density were obtained in the top region of the weld due to liquid CO2 cooling.A large number of{1012}twins and second-phase particles were also induced in these refined grains.The basal texture intensity was significantly reduced due to the appearance of{1012}twins.The top region showed the higher strength and elongation compared with the bottom region,and the welding efficiency reached 93%.This work provided a simple and efficient strategy for manufacturing a gradient structure in the FSW Mg alloy joint.
