Strengthening-toughening of 7xxx series high strength aluminum alloys by heat treatment
来源期刊：中国有色金属学报(英文版)2003年第3期
论文作者：陈康华 黄兰萍
文章页码：484 - 490
Key words：aluminum alloys; 7000 series aluminum alloy; heat treatment; stress corrosion; precipitation
Abstract: The effects of stepped solution heat treatments on the dissolution of soluble remnant constituents and mechanical properties of 7055 aluminum alloy were investigated. It was shown that a suitable pretreatment at lower temperature can enable complete dissolution of the constituent particles in 7055 alloy without overheating by subsequent high temperature solution treatment. This in turn increased the tensile strength and fracture toughness of 7055 alloy to 805MPa and 41.5MPa·m1/2 respectively, with approximately 9% tensile elongation. The near-solvus pre-precipitation following after high temperature solution treatment was also studied on 7055 aluminum alloy. The effect of the pre-precipitation on the microstructure, age hardening and stress corrosion cracking of 7055 alloy was investigated. The optical and transimission electron microscopy observation show that the near-solvus pre-precipitation can be limited to grain boundary and enhance the discontinuity of grain boundary precipitates in the subsequent ageing. The stress corrosion cracking resistance of aged 7055 alloy can be improved via the pre-precipitation with non-deteriorated strength and plasticity.
