Research on Microstructure and Mechanical Properties of Friction Stir Lap Welded Aluminum/Brass Dissimilar Joint

doi:10.3901/JME.2019.06.039

Abstract

Abstract: 5052 aluminium alloy and H62 brass dissimilar metals are friction stir lap welded. The rotation speed is kept constant at 1 000 r/min with welding speed varying from 100 mm/min to 300 mm/min. Microstructure and mechanical properties of the joint are studied. The joint at Al side is divided into weld nugget zone, thermo-mechanically affected zone and heat-affected zone. Grains are refined within the area contacted with the welding tool at Al side. Obvious dividing line is formed between the two plates at the Al/Brass interface with the existence of brass with different size and shape. There are interface compounds produced and mechanical mixture of brass and aluminium produced near the brass at the interfaces. Hardness distribution of joint cross-section along the aluminum side show hardness at welding nugget are highest and the lowest appear on the heat affected zone. Hardness at the interface is significantly higher than that of Al and Brass base metal. With the increasing welding speed, the tensile shear strength increases first and then decreases. Tensile test indicates that the joint fractures at interface layer of the brass side with cleavage fracture surface.

Key words: Al/Cu dissimilar metals, friction stir lap welding, mechanical properties, microstructure

CLC Number:

TG453

YU Mingrun, ZHAO Hongyun, JIANG Zhihua, ZHOU Li, HUANG Yongxian, SONG Xiaoguo. Research on Microstructure and Mechanical Properties of Friction Stir Lap Welded Aluminum/Brass Dissimilar Joint[J]. Journal of Mechanical Engineering, 2019, 55(6): 39-45.

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