Residual Stress During Stamping-Forging of 2024 Aluminum Alloy Sheet

Stamping-forging processing can significantly reduce the residual stress of sheet metal parts. First, the variation of residual stress field during stamping-forging processing and the influence of relative bending radii and forming temperature on the residual stresses of stamping-forged V-shaped parts have been studied by finite-element analysis. Then, the stamping-forging processing has been employed in the forming of 2024 aluminum alloy square cups with nonuniform thickness to investigate the effects of process parameters, such as punch radius, die entrance radius, and die corner radius, on the residual stresses of stamping-forged square cups. The optimum process parameters of stamping-forging have been obtained, which can produce square cups with low residual stresses, that is, the maximum residual stress value can be reduced from 190 MPa for deep drawn square cups to around 60 MPa for stamping-forged square cups. Therefore, it is indicated that the stamping-forging processing can significantly reduce the residual stress of sheet metal parts.