Porosity and microstructure characteristic of 1060Al laser welded joint under high frequency micro-vibration condition

The 5 mm thick 1060Al was welded by the coupling of laser and high-frequency vibration. Vibration effect on welding formation, size, quantity and distribution of porosities, microstructure and microhardness of the joint were researched. The influence of the flow of the molten pool on the hole position distribution was also studied. The results showed that the best welding formation could be got with 1 173 Hz vibration frequency. The grain refinement was the most obvious. The best surface appearance could be obtained. The average value of welding zone microhardness increased from 27.2 HV without vibration to 29.4 HV with vibration, which increased by 8.1%. Under the condition that vibration frequency was 923 Hz, the porosities were effectively suppressed. The flow of the molten pool and the stability of laser keyhole were influenced by frequency of micro-vibration which had certain relevance with the welding porosity formation. The pores were gradually gathered to the welding surface with frequency of vibration increasing.