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...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 805 MPa and 41.5 MPa·m 1/2 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.展开更多
The effects of impurity element of Fe and microelements of Zn, Cr and Ti on the constituents, dispersoids, grain size, mechanical properties and formability of Al-1.3Mg-1.2Si-0.6Cu-0.3Mn alloy were investigated in the...The effects of impurity element of Fe and microelements of Zn, Cr and Ti on the constituents, dispersoids, grain size, mechanical properties and formability of Al-1.3Mg-1.2Si-0.6Cu-0.3Mn alloy were investigated in the present work by analyzing microstructures, phase composition, mechanical tests. The results indicated that with the increase of Fe content, the insoluble constituents increased, and the mechanical properties and r15 of alloy sheets debased, which can be recovered by the addition of microelements Zn, Cr and Ti. Al-1.3Mg-1.2Si-0.6Cu-0.3Mn alloy sheets in the T4 temper are difficult to strengthen with paint-bake treatment in automobile factory.展开更多
文摘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 805 MPa and 41.5 MPa·m 1/2 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.
文摘The effects of impurity element of Fe and microelements of Zn, Cr and Ti on the constituents, dispersoids, grain size, mechanical properties and formability of Al-1.3Mg-1.2Si-0.6Cu-0.3Mn alloy were investigated in the present work by analyzing microstructures, phase composition, mechanical tests. The results indicated that with the increase of Fe content, the insoluble constituents increased, and the mechanical properties and r15 of alloy sheets debased, which can be recovered by the addition of microelements Zn, Cr and Ti. Al-1.3Mg-1.2Si-0.6Cu-0.3Mn alloy sheets in the T4 temper are difficult to strengthen with paint-bake treatment in automobile factory.
