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Improving Thickness Uniformity of Ti3Al Sheet Metal SPF by Preforming

Ti3Al intermetallic alloy is a hard formed material with many advantages for aviation and aerospace applications. Superplastic forming (SPF) is an ideal process for Ti3Al alloy to form sheet metal component. The thickness distribution of U cross-section circular parts, which were superplastically formed in two different female die cavity, were predicted by FEM software. According to female die forming thickness distribution, preforming die cavity was designed and was optimized by FEM software. Superplastic bugling tests with and without preforming were carried out. The thickness of parts were measured and compared with predictions by FEM software. The results showed that preforming can promote thickness uniformity efficiently in female die forming. In this experiment, the thickness difference range of the part formed with preforming reduced 75.8% compared with part formed without preforming.