Effect of laser shock peening on residual stress and fatigue property of 7050 aluminium alloy with hole

doi:10.13251/j.issn.0254-6051.2021.11.036

Abstract

Abstract: Effect of laser shock peening on microhardness, residual stress and fatigue property of the 7050 T7451 aluminium alloy with hole was studied. The results show that when the laser energy is 30 J, circular spot diameter is 4 mm and the shock times are twice, the microhardness of the 7050 aluminium alloy increases obviously, the surface microhardness increases by 12% compared with the base material, with the hardened layer of 1 mm. The amplitude of residual compressive stress exceeds 300 MPa, and the influence depth of residual compressive stress can reach about 1 mm, which is significantly greater than the depth of influence layer strengthened by shot peening. The residual compressive stress can improve the initiation resistance of fatigue crack, and the deeper influence layer of residual compressive stress is beneficial to prolong the crack growth life. Laser shock peening can obviously improve the fatigue life of the aluminum alloy with hole, which is increased by 4.7 times to 17.6 times compared to that of the untreated specimen, and the fatigue life gain and stability are obviously better than those of shot peening.

Key words: laser shock peening, 7050 T7451 aluminium alloy, hole structure, microhardness, residual compressive stress, fatigue property

CLC Number:

TG156

Han Peipei, Jiao Qingyang, Quan Chunyi, Zhao Dong, Sun Rujian, Che Zhigang. Effect of laser shock peening on residual stress and fatigue property of 7050 aluminium alloy with hole[J]. Heat Treatment of Metals, 2021, 46(11): 202-206.

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