LI Ying, HOU Zhenguo, NIU Xujing.Surface Nano-treatment of 7075-T651 AluminumAlloy and its Strengthening Mechanism[J].Electric Welding Machine, 2022, 52(10): 57-61.
The surface nano-treatment of 7075-T651 aluminum alloy was realized by surface mechanical rolling treatment (SMRT) method. Electron backscatter diffraction (EBSD) results show that a 500 μm thick gradient nano-layer is formed on the surface of SMRT sample, the thickness of the surface nano-crystal layer is about 50 μm and the average grain size is about 200 nm. The thickness of the subsurface deformation grain layer is about 450 μm, and the average grain size is about 2 µm. The base metal shows typical rolling grain characteristics, and the average grain size is about 5 µm. The tensile test results show that the tensile strength, yield strength and elongation of the original 7075-T651 aluminum alloy are 545 MPa, 506 MPa and 17.3% respectively. After SMRT, the tensile strength, yield strength and elongation are 620 MPa, 536 MPa and 13.4% respectively. The strength of the sample significantly improves, and the toughness does not significantly decrease. Gradient nanostructures are introduced into the surface layer of the material by SMRT. This special structure has excellent matching of strength and plasticity, which is the main reason for the improvement of mechanical properties.
关键词
7075铝合金梯度纳米结构表面机械滚压处理表面纳米化处理
Keywords
7075 aluminum alloygradient nanostructuresurface mechanical rolling treatmentsurface nano-treatment
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