Forming, Microstructure and Mechanical Properties of 7075 Al Joint Prepared Via Laser Beam Oscillating Welding

doi:10.3901/JME.2025.04.086

Abstract

Abstract: 7 Series aluminum alloy is known as an important branch of the aluminum alloys due to its excellent specific strength. Compared with other series of aluminum alloys, 7 series aluminum alloy are limited to the large-scale application of complex structural parts due to the poor welding characteristics. Therefore, the realization of 7 series aluminum alloy fusion welding connection is of great significance to promote its application in large complex structural parts. the formation, microstructure and mechanical properties of 7075 aluminum alloy are systematically studied by high power, high velocity and beam oscillation laser welding technology. The process parameters are optimized through orthogonal experiments, and the results show that the mechanical properties of the joint are optimal when the laser power is 4 500 W, the line energy is 80 J/mm, the swing amplitude is 1 mm, and the swing frequency is 200 Hz. A joint with an average tensile strength of 352 MPa is obtained. Based on two characteristic parameters describing the actual energy distribution during laser swing welding, a quantitative relationship between process parameters, weld morphology, and joint strength is established. The results indicated that the weld is composed of equiaxed crystal region, columnar crystal region and fine equiaxed crystal region. The EBSD image of tensile fracture shows that 7075 welding joint breaks in the equiaxed crystal region in the middle of weld during the tensile process.

Key words: laser beam oscillating welding, 7075 aluminum alloy, microstructure, mechanical properties

CLC Number:

TG456

MI Gaoyang, JIANG Yiming, WANG Chunming, ZHANG Mingyang, HU Yiyang, XIAO Yongkang, ZHAI Chuncheng, OUYANG Qiubao. Forming, Microstructure and Mechanical Properties of 7075 Al Joint Prepared Via Laser Beam Oscillating Welding[J]. Journal of Mechanical Engineering, 2025, 61(4): 86-95.

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