Mechanical properties of a novel high-strength aluminum-lithium alloy
As a heat treatable aluminum alloy to be used in T6 and T8 temper, belongs to Al-Cu-Li system, a novel high-strength aluminum-lithium alloy 2A97 was developed. In order to improve the relationships of strength and ductility and fracture toughness, and to urge the applications in the aeronautical and aerospace industries, the effects of normal heat treatments and thermomechanical heat treatments on the mechanical properties and fracture toughness were investigated by Transmission Electron Microscope(TEM), Scanning Electronic Microscope (SEM), tensile test, and fracture toughness test. The results show that for the alloy aged at 135 ℃ for 24 h after quenching and 4 percent plastic deformation, its microstructures are strengthened by strain hardening and precipitation hardening, consisting of fine T1 phase, θ″/θ′ phase and δ′ phase densely and homogeneously distributed in the matrix. It yields optimum relationship of strength and ductility, fracture toughness, its σ0.2, σb and δ5 are 454 MPa, 536 MPa, and 11.8％, respectively. It yields 43.5 MPa·m1/2 of Kq values higher than that of 42.5 MPa·m1/2 in T6 temper. The fracture morphologies of impact tensile samples of fracture toughness test and normal tensile test were observed, indicating the dominance of intergranular failure and subintergranular failure with some dimples and trangranular failure.
Strengthening and toughening mechanism 2A97 aluminum-lithium alloy fracture toughness thermomechanical heat treatment
Zhishan Yuan Zheng Lu Youhua Xie Xiuliang Wu Shenglong Dai Changsheng Liu
General Research Institute for Non-Ferrous Metals, Grikin Advanced Materials Co., Ltd.,Beijing 10008 Beijing Institute of Aeronautical Materials, Beijing 100095, China School of Materials & Metallurgy, Northeastern University, Shenyang 110004, China
国际会议
11th IUMRS International Conference in Asia(第十一届国际材联亚洲材料大会 IUMRS-ICA 2010)
青岛
英文
385-389
2010-09-25（万方平台首次上网日期，不代表论文的发表时间）