The ultrasonic-assisted laser shock peening (ULSP) technique improves the balance between tensile strength and elongation of aluminum alloys through the combined effects of laser shock peening (LSP) and ultrasonic rolling (UR). The 7075–T6 aluminum alloy was selected as the subject of study

and ULSP treatment was conducted. The metallographic structure

phase composition

surface morphology

microhardness

and residual stress were systematically examined. By analyzing the stress-strain curves

fracture morphology

and the improvement mechanism of tensile properties after ULSP treatment was elucidated. The results show that the ULSP treatment induces a significant grain refinement eff

ect

resulting in a gradient structure comprising a severely refined grain layer

a refined grain layer

and the original coarse grain layer. Furthermore

the ULSP treatment effectively mitigated the issue of increased surface roughness associated with LSP treatment. The surface roughness S

a

and profile roughness R

a

of the ULSP samples are reduced by 74.0% and 82.3%

respectively

compared to the LSP samples. Benefiting from the grain refinement effect

high compressive residual stress

and low surface roughness

the ULSP samples achieved a substantial increase in tensile strength with only a minor sacrifice in elongation. Specifically

the tensile strength is enhanced by 13.3%

while the elongation is only decreased by 11.7%.