Exploration of thinning behavior and microhardness in single point incremental forming of aviation grade AA7079 aluminum alloy

Purpose This paper targeted to experimentally investigate the use of single point increment forming (SPIF) to fabricate cone-shaped components from aviation grade AA7079 aluminum alloy, with a focus on critical performance metrics such as microhardness (MH) and thinning percentage (TN%). A detailed examination of various process parameters – including tool diameter (TD), rotational spindle speed (RSS), vertical step size (VSS), feed rate (FR) and sidewall angle (SWA) – was conducted to assess their influence on material behavior. The findings offer important insights into how AA7079 deforms under different processing conditions, aiding in the optimization of SPIF parameters for improved product quality. Design/methodology/approach The experimental approach employed design of experiments (DoE) principles, with test runs analyzed employing response surface methodology. Data was further evaluated through Analysis of Variance (ANOVA) and desirability function analysis (DFA) to identify key influencing factors and optimize outcomes. The study revealed that SWA, VSS, FR, RSS and TD all played an essential role in determining MH and TN%. In addition, DFA and ANOVA have been utilized to identify critical process parameters and their interactions. These statistical techniques aid in developing mathematical models for response variables and optimizing process settings. Findings The best values of MH and TN% have been recommended as 147.8 and 66.9%, respectively, based on the parameter configuration of TD of 7 mm, SWA of 70°, VSS of 1 mm, RSS of 2000 rpm and FR of 2500 mm/min. Furthermore, the desirability values were 0.832 for MH, 0.933 for TN% and 0.881 for the combined desirability index (both MH and TN%), indicating effective optimization. Confirmation experiments validated the model’s accuracy, with an acceptable percentage error between predicted and actual values, demonstrating the reliability of the developed models. Moreover, the validation experiments were conducted to detect any discrepancies from the anticipated optimal value. Originality/value The various challenges associated with the productive forming of aviation grade AA7079 aluminum alloy have been explored experimentally. Further, the practical impact of considered process variables on the MH and TN% while processing aviation grade AA7079 aluminum alloy has been explored with the SPIF process. The utility of designed experiments has further made the attempted experimental analysis more fruitful and qualitative too.