Effect of Stepped Aging Treatment on Microstructure and Properties of AA7085 Aluminum Alloy
The effect of stepped aging treatment including two-stepped retrogression aging and retrogression reaging treatment on the mechanical properties, electrical conductivity and the microstructure of AA7085 has been investigated. Electron microscopy observations were used to analyze the microstructures and tensile fracture surfaces of AA7085 processed via various treatment schedules. Besides, X-ray diffractometer and differential scanning calorimeter were used to explore the thermodynamic factors of heat treatment. Through the investigation of the effect of the retrogression time on the properties and microstructure of AA7085, the optimized retrogression time was confirmed. The results of comparing retrogression aging and retrogression reaging treatment showed that through RRA treatment, higher conductivity and fracture toughness were gained. Through the optimized RRA treatment based on appropriate retrogression time, the tensile strength, elongation, fracture toughness and conductivity of AA7085 were raised to 660MPa, 12%,36.6MPa•m1/2and 38.1%IACS.
C. M. Li et al., "Effect of Stepped Aging Treatment on Microstructure and Properties of AA7085 Aluminum Alloy", Advanced Materials Research, Vols. 228-229, pp. 968-974, 2011