An Investigation on the Effects of the Process Variables on the Warm Incremental forming of the Titanium Ti-6Al-4V

The incremental forming is an attractive sheet forming operation. Finite element analyses specially at elevated temperatures for important alloys such as titanium Ti-6Al-4V are very affordable. In this study, warm incremental forming of Ti-6Al-4V is simulated and validated using different experimental outputs, namely forming limit diagrams, the drawing depth and the minimum thickness of the sample. Then, the effects of the process parameters on the forming forces are investigated considering heat generation during the process. It is found that the maximum amounts of the forming forces belong to the vertical component. In addition, any decrease in the initial temperature of the sheet as well as increase in the vertical pitch and/or tool diameter could cause certain increases in vertical forces. Furthermore, it is shown that the specimen geometry and the material can significantly influence the forming forces. Effective strain distributions also illustrate that the major sheet stretching occur in the centerline of the groove. Finally, the buckling and stress analyses of the tool imply that the tool instability and damage can mainly be caused by the tensile bending stresses.