Abstract: Non-uniform deformation within forgings can result in much difference in microstructure and property. The preform design applying the method for preform optimization based on FEM can improve the deformation uniformity within forgings effectively. The fundamental of this method is formulated firstly. As an example, the preform optimization for a typical IN718 turbine disk forging is performed. The results for the optimal billet are presented and compared with those of the cylinder billet. The die forging experiments with different billets are carried out to validate this method. The results show that the deformation uniformity within the turbine disk can be improved evidently by application of the proposed method.

Key words: preform optimization, FEM, IN718 alloy, turbine disk forging, deformation uniformity