Influence of Cold Rolling and Annealing on the Tensile Properties of Aluminum 7075 Alloy

The present work reports the effect of cold rolling and subsequent annealing at different temperatures on the tensile behavior of 7075 aluminum alloy. The cold rolling has been carried out in between 12-28% and was annealed at various temperatures in the range of 225-325 °C for 5 min. Hardness test and tensile tests were carried out to evaluate tensile and ductility parameters. All the tensile specimens were taken from the transverse direction of the cold rolled and annealed sample. It has been observed that the cold rolling has a significant effect on the increase in the yield strength and lowering the ductility of the alloy. It was also observed that the cold rolled samples, annealed at 275 °C showed lower total elongation in the transverse direction, while for samples annealed at high temperatures the total elongation values were observed to be high. In general it is also observed that formability (UTS/σy) of cold worked and annealed samples were high when compared to cold worked samples. Fractographic study using SEM analysis was carried out for all the conditions. Failure took place by formation of dimples indicating ductile fracture