Finite element analysis for preheating process of extrusion die tooling

In canned extrusion of gamma titanium aluminide, preheating of die tooling can help not only to improve the uniformity of flow patterns and attain homogenous microstructure, but also to relieve thermal stress and reduce tendency of thermal fatigue, as well as reduce load of die tooling. In this paper, the finite element analysis was performed to investigate the preheating process of die tooling with heated graphite rods. The critical preheating time, the appropriate number of graphite rods and the temperature distribution of die tooling were determined. Meanwhile, optimization of preheating process parameters were carried out, making it possible to preheat die tooling to 260°C with uniform temperature distribution of the whole die tooling and without overheating of tooling surface. This can be achieved by heating for 876 s, 672 s, 600 s, 576 s, 560 s for the five graphite rods, respectively.