Abstract
Constant-speed and speed-contro11ed superplastic forging processes of a titanium alloy into a watch case back have been analyzed by the finite element method (FEM). In the superplastic forging, it generally takes a long time for shaping and it is difficult to decide shaping conditions and dimensions of preforms and dies. It is possible to evaluate the forging load, stress distribution and deformation state by this method even in the speed-controlled forging whose speed is decreased step by step. By using the FEM analysis, it is found that the speed-controlled forging may be effective for the decrease in the forging 1oad and improvement of the shaping abillty.
