Study On Microstructure And Properties Of 7A04 Aluminum Alloy After High Temperature Deformation

As science and technology and defense industries, people are increasingly demanding high strength aluminum alloy high, at present, industrial production increased in high strength aluminum alloy as much as possible the heating temperature, while the deformation temperature, high strength aluminum alloy Relatively narrow range, therefore, high strength aluminum alloy high temperature deformation, the need for a lot of work.In this paper, hardness, room temperature tensile, metallographic, SEM, analysis of the 7A04 aluminum alloy at different deformation temperature and deformation microstructure and properties of the number of changes under the law for the thermal processing system has been developed to provide reference and basis.The results show that, with the deformation temperature, T5 and T6 state alloy state strength, hardness, plasticity showed increased first and then decreased, 480℃when the highest point, the temperature continues to rise, performance degradation. with Deformation increase in the number, T5 alloy strength, hardness increase, plastic drop; T6 alloy is less than four times the number when the deformation, strength, hardness and ductility are increased, forming five times lower.7A04 aluminum alloy high temperature deformation based mainly on dynamic recrystallization. Deformation temperature, can promote the dynamic recrystallization manner; appropriate increase in the number of deformation, but also can promote the dynamic recrystallization to proceed smoothly.The number of deformation temperature and deformation mode of the fracture has implications, 7A04 aluminum alloy fracture mode mainly intergranular fracture and dimple fracture, had burned, the binding force between the grain boundary is weakened, brittle fracture occurs along the grain; T6 state than the T5 state dimple large number of small, poor toughness. 7A04 aluminum alloy had burned, the sharp decline in overall performance, material scrap, industrial production should be avoided.Through this experiment, the best 7A04 aluminum alloy forming process for forming four 480℃, and then T6 (470℃×45min +130℃×16h aging solution) heat treatment, the mechanical properties can be achieved:σb = 590.8 Mpa,σ0.2 = 531.9Mpa,δ= 12.5%,ψ= 18.4%.