An experimental study of forming force and hardness of deformed sheet in induction heated incremental forming of AA6061 alloy

Abstract

Incremental Sheet Forming (ISF) is an advanced, highly flexible, and die-less forming process, making it ideal for the cost-effective production of small-batch sheet metal components. Integration of heat with ISF plays a crucial role in reducing forming forces and enhancing product quality. This study investigates the Induction Tool Heated ISF (ITHISF), where the forming tool is heated using an induction coil. The main focus is on the influence of feed rate, wall angle, step depth, and tool temperature on forming forces as well as the hardness of the sheet of AA6061 alloy. Additionally, the effects of solid lubricant (MoS2) and liquid lubricant (machine oil) on forming forces and hardness are examined; machine oil provided superior performance. A reduction of ∼66.8 N of steady axial forming force and 2 HV of microhardness was observed from room temperature to a tool temperature of 250°C. Sufficiently accurate linear models could be fitted to experimental data on force. A simple analytical formula from the literature could predict experimental results within an error of ∼20%, highlighting the efficacy of that model. These findings are a step toward the optimization of heat-assisted ISF.