The effect of pre-ageing temperature and retrogression heating rate on the microstructure and properties of AA7055

Abstract. fect of pre-ageing temperature and retrogression heating rate variations on the mechanical properties and electrical conductivity of the RRA treated AA7055 has been investigated. The microstructures under various RRA treated samples are discussed in detail. The results reveal that, near peak aged state plus slow retrogression heating is more applicable for industrial processing. Under the pre-ageing at 105 °C/24 h and a slow retrogression heating rate of 3 °C/min condition, RRA-treated samples possess a better combination of both strength and electrical conductivity than the T6 or T73 states.