Die and workpiece have the same, constant temperature throughout the isothermal forming process. Complex geometries with high dimensional accuracy can be manufactured, and parts with high degrees of deformation are feasible. The major strain rate and flow stresses are very low, preserving the die and supporting material distribution in the cavity. Isothermal forming presses from Schuler offer a highprecision control of ram speed and ram force, which can be adapted to the changing part geometry during the forming process.
Removal of Residual Stress with Calibration Presses
Calibration or thermal fixation can be applied to remove residual stress of the workpiece, caused for example by previous (cold) trimming operations. Parts are subject to a constant pressure in the press die, with the furnace heated slightly below forming temperature. Thermal stabilization can last several minutes. Calibration presses from Schuler keep the selected pressure constant during the calibration or fixation process, which can last up to several minutes.