Effect of Exterted Ultrasonic Power on Microstructure and Properties of Dissimilar Al/Mg Alloys UVeFSW Joints

doi:10.3901/JME.2020.06.024

Abstract

Abstract: The ultrasonic vibration enhanced friction stir welding(UVeFSW) process is employed to join dissimilar aluminum-magnesium alloys. Three levels of ultrasonic power, i.e., low (75 W), medium (220 W) and high (550 W), are selected to conduct UVeFSW experiments. The effects of ultrasonic power levels on the welding load, the weld macrographs, the intermetallic compound layers and the tensile properties of weld joints are compared and analyzed. The results show that when the applied ultrasonic power is appropriate, the best synergistic effect can be obtained between the ultrasonic effect and the thermo-mechanical-material flow coupling mechanism of friction stir welding process itself. The effect of ultrasonic vibration in friction stir welding process is not always enhanced with the increase of ultrasonic power; only when the ultrasonic power is moderate, the effect of improving the welding process and joint structure and properties is the greatest. The experimental results are explained preliminarily in terms of sound softening effect, friction reduction effect and dislocation annihilation.

Key words: friction stir welding, ultrasound power, aluminum alloy, magnesium alloy, joint microstructure and property

CLC Number:

TG453

ZHAO Junjie, SU Hao, SHI Lei, WU Chuansong. Effect of Exterted Ultrasonic Power on Microstructure and Properties of Dissimilar Al/Mg Alloys UVeFSW Joints[J]. Journal of Mechanical Engineering, 2020, 56(6): 24-32.

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