Experimental Study on Effects of Process Parameters on Superplastic Deformation Ability of 7075 Aluminium Alloy Using Taguchi Method

Superplasticity is the ability of an alloy to be permanently stretched to very high elongation within a limited range of conditions (grain size, deformation temperature and strain rate). The 7075 aluminium alloy superplastic sheet was used in this study. The AA 7075 sheets were prepared with microstructure using the thermomechanical treatment. The average grain size was 13 μm. The main purpose of this study is to investigate the influence of deformation parameters such as temperature and strain rate, on the deformation ability of 7075 aluminium alloy. The deformation ability of 7075 alloy was investigated under isothermal tensile tests. The results were analyzed to determine the optimum strain rate and temperature by using the Taguchi method and analysis of variance. The maximum superplastic elongation and the maximum stress were determined at different initial strain rates (5 × 10−4 s−1, 10−3 s−1 and 1,5 × 10−3 s−1) and temperatures (5000C, 5150C and 5300C), respectively. The optimum process parameters were obtained by analyzing the signal to noise ratio. The experimental results revealed that the effect of strain rate was more influential on the deformation ability than that of the temperature. The optimum results were achieved at the temperature of 530 °C and the strain rate of 10−3 s−1, respectively. © Springer Nature Switzerland AG 2020.