Investigating the effect of hot preforming combined with superplastic forming on thickness distribution and forming time of Ti-6Al-4V alloy using finite element analysis

The present work focuses on the development of a new superplastic forming (SPF) that utilizes hot preforming to improve thickness distribution and decrease forming time. For this purpose, finite element analysis (FEA) was employed as an efficient tool to indicate feasibility of the new method by designing the appropriate die geometry. The experimental tests were performed to find the tensile properties of Ti-6Al-4V alloy at different temperatures and angles. Detailed FEA technique was employed to model the SPF process by a constitutive model that considers both microstructural features and geometrical instabilities. The variations of the forming time and distribution of thickness due to the variation of the forming parameters such as strain rate and friction coefficient were studied to compare the results with the results of hot preforming combined with SPF process. The obtained results from FEA showed that this new method can provide a good thickness distribution, so that the thickness variation reduced from 44% to about 21% and the forming time considerably reduced from 1100 to 610 s.