Description85 Comparative investigations of superplastic behavior and formability of commercial sheets with microcrystalline (MC, a grain size of 3-5 mm) and submicrocrystalline (SMC, a grain size of 0.3 mm) structure out of titanium Ti-6Al-4V alloy have been performed. It is shown that the decrease in the grain size leads to a significant decrease in the temperature of superplastic deformation to 650°C, or to a shift of superplasticity optimum to higher strain rates at temperatures above 750°C. Unlike commercial sheets, the sheets with SMC structure are characterized by isotropy of mechanical properties. The process of superplastic forming (SPF) of sheet samples out of Ti-6Al-4V alloy with SMC structure in the matrix with the cylindrical hole at the temperature 700°C was investigated. It has been established that application of material with initial SMC structure provides improving characteristics of polythickness and decreasing the temperature of SPF by 200°C. High Performance Metallic Materials for Cost Sensitive Applications
