Study on the Laser Wire Filling Welding Process and Properties of 6061-T6 Aluminum Alloy Lap Joints

Shuming Zhang; Yi Zhong; Jun Lu; Jipeng Zhu; Yuquan Wu

doi:10.62051/ijmsts.v5n2.06

Authors

Shuming Zhang
Yi Zhong
Jun Lu
Jipeng Zhu
Yuquan Wu

DOI:

https://doi.org/10.62051/ijmsts.v5n2.06

Keywords:

6061 aluminum alloy, Laser wire filling welding (LWFW), Microstructure, Tensile strength, Process optimization

Abstract

This study systematically investigates the laser wire filling welding (LWFW) process of 6061-T6 aluminum alloy lap joints using ER5356 filler wire. The influence of critical process parameters, including laser power, welding speed, and wire feed speed, on weld formation, microstructural evolution, and mechanical properties was evaluated. The results demonstrate that line energy input, determined by laser power and welding speed, is the primary factor governing penetration depth and macroscopic quality. An increase in laser power significantly enhances penetration by stabilizing the keyhole effect, while higher welding speeds refine the Heat-Affected Zone (HAZ) grains by reducing thermal residence time. Microstructural analysis revealed distinct zoning, with fine equiaxed grains in the weld metal (WM) and columnar crystals near the fusion line. The tensile strength of the joints is determined by the synergy between the effective bonding area (penetration depth) and fine-grain strengthening. Under the optimized conditions of 2.8 kW laser power, 25 mm/s welding speed, and 4.0 m/min wire feed speed, high-quality joints with a tensile strength of 195 MPa (approximately 63% of the base metal strength) were obtained. This research provides a theoretical and technical basis for the application of LWFW in automotive aluminum component manufacturing.

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