The effects of ultrasonic vibration assisted（UVA） treatment on the microstructures and mechanical properties of MB3/AZ31 dissimilar magnesium（Mg） alloy joints were studied by microstructural characterization, micr...The effects of ultrasonic vibration assisted（UVA） treatment on the microstructures and mechanical properties of MB3/AZ31 dissimilar magnesium（Mg） alloy joints were studied by microstructural characterization, micro-hardness testing and tensile testing. Results indicate that the welding pores are eliminated and coarse a-Mg grains of fusion zone are refined to 26 μm, owing to the acoustic streaming effect and cavitation effect induced by the UVA treatment with an optimal ultrasonic power of 1.0 kW.In addition, Mg;Al;precipitation phases are fine and uniformly distributed in the whole fusion zone of weldment. Micro-hardness of fusion zone of the Mg alloy joints increases to 53.5 HV after UVA process,and the maximum tensile strength with optimized UVA treatment increases to 263 MPa, which leads to fracture occurrence in the Mg alloy base plate. Eventually, it is experimentally demonstrated that robust MB3/AZ31 Mg alloy joints can be obtained by UVA process.展开更多
基金the financial support by the National Natural Science Foundation of China(No.51575067)the Major and Special Project by Ministry of Science and Technology(No.2012ZX04010-081)
文摘The effects of ultrasonic vibration assisted（UVA） treatment on the microstructures and mechanical properties of MB3/AZ31 dissimilar magnesium（Mg） alloy joints were studied by microstructural characterization, micro-hardness testing and tensile testing. Results indicate that the welding pores are eliminated and coarse a-Mg grains of fusion zone are refined to 26 μm, owing to the acoustic streaming effect and cavitation effect induced by the UVA treatment with an optimal ultrasonic power of 1.0 kW.In addition, Mg;Al;precipitation phases are fine and uniformly distributed in the whole fusion zone of weldment. Micro-hardness of fusion zone of the Mg alloy joints increases to 53.5 HV after UVA process,and the maximum tensile strength with optimized UVA treatment increases to 263 MPa, which leads to fracture occurrence in the Mg alloy base plate. Eventually, it is experimentally demonstrated that robust MB3/AZ31 Mg alloy joints can be obtained by UVA process.
