Effect of Process Parameters on the Forming Limit Angle of AA2024 Aluminum Alloy in Belt-Heated Incremental Sheet Forming

In the belt-heated incremental sheet forming process, the influence of process parameters on the forming limit angle significantly affects the forming accuracy and quality of components. Through macro and micro experiments, this study comprehensively analyzed the effect of key process parameters on the forming limit angle and identified forming temperature, tool head diameter, and step down as the primary factors that enhance the forming limit angle. Building on this, the dislocation density and grain size of the material under various forming temperatures, tool head diameters, and step-down values were investigated, clarifying the influence of these parameters on dislocation density and grain size in belt-heated incremental sheet forming. Furthermore, the dislocation density and grain size in the cross-section of the deformed region were calculated through micro-tests, revealing the variation patterns of dislocation density and grain size under different process conditions. These findings verified the macro–micro mechanism of the effect of process parameters on the forming limit angle and led to the establishment of a control method for the forming limit angle in belt-heated incremental sheet forming.