Homogenization annealing of the 7050/6009 bimetal slab prepared by direct-chill casting was investigated and its effects on microstructural evolution, composition distribution and mechanical properties in the interfac...Homogenization annealing of the 7050/6009 bimetal slab prepared by direct-chill casting was investigated and its effects on microstructural evolution, composition distribution and mechanical properties in the interfacial region of the bimetal were studied. The results show that the optimized homogenization annealing process was 460℃for 24 h. After homogenization annealing, the Zn-rich phases and Al15（FeMn）3Si2phases were precipitated at the interface of the bimetal. The diffusion layer thickness of homogenized bimetal increased by 30 μm from 440 to480℃for 24 h, while it increased by 280 μm from 12 to 36 h at 460℃. The Vickers hardnessesat 6009 alloy side and interface of the bimetal decreased after homogenized annealing and grain coarsening was considered asthedominating softening mechanism.The hardness variation at 7050 alloy side was complicated due to the combined action of solution strengthening, dispersion strengthening and dissolution of reinforced phases.展开更多
基金Projects(51375070,51574058)supported by the National Natural Science Foundation of China
文摘Homogenization annealing of the 7050/6009 bimetal slab prepared by direct-chill casting was investigated and its effects on microstructural evolution, composition distribution and mechanical properties in the interfacial region of the bimetal were studied. The results show that the optimized homogenization annealing process was 460℃for 24 h. After homogenization annealing, the Zn-rich phases and Al15（FeMn）3Si2phases were precipitated at the interface of the bimetal. The diffusion layer thickness of homogenized bimetal increased by 30 μm from 440 to480℃for 24 h, while it increased by 280 μm from 12 to 36 h at 460℃. The Vickers hardnessesat 6009 alloy side and interface of the bimetal decreased after homogenized annealing and grain coarsening was considered asthedominating softening mechanism.The hardness variation at 7050 alloy side was complicated due to the combined action of solution strengthening, dispersion strengthening and dissolution of reinforced phases.
