Effect of Laser Shock Peening on the Properties of Al-Zn-Mg Thin-walled Structures Fabricated by Wire Arc Directed Energy Deposition

doi:10.3901/JME.260075

Abstract

Abstract: To address the issues of high internal stress and porosity defects in thin-walled high-strength Al-Zn-Mg alloy components fabricated by wire arc directed energy deposition (WA-DED), this study investigates the effect and mechanism of laser shock peening (LSP) as a post-treatment process. The influence of LSP on the mechanical properties, residual stress, microstructure evolution, and porosity of as-deposited Al-Zn-Mg alloys is systematically studied. Experimental results show that LSP introduces significant residual compressive stress inside the specimens, with an affected depth of approximately 1 mm. Compared to the as-deposited condition (yield stress: 266.6 MPa±0.7 MPa, ultimate tensile strength: 406.5 MPa±2.0 MPa), the yield strength and ultimate tensile strength of the Al-Zn-Mg alloy after LSP increased by 38.1% and 16.1%, reaching 368.1 MPa±5.1 MPa and 471.9 MPa±9.5 MPa, respectively. The remarkable improvement in mechanical properties is attributed to the generation of high-density dislocations within the bulk and the formation of numerous nanograins on the LSP-affected surface. The synergistic effects of dislocation strengthening and grain refinement are responsible for the enhanced mechanical performance of the LSP-treated samples.

Key words: additive manufacturing, wire arc directed energy deposition, laser shock peening, Al-Zn-Mg alloy, mechanical properties

CLC Number:

TH164

LI Kai, JIANG Xiao, FANG Xuewei, CHEN Ruikai, WANG Hang, LI Changze, HUANG Ke, LU Bingheng. Effect of Laser Shock Peening on the Properties of Al-Zn-Mg Thin-walled Structures Fabricated by Wire Arc Directed Energy Deposition[J]. Journal of Mechanical Engineering, 2026, 62(3): 137-145.

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