Study on the superplastic behavior of Ti-15-3 alloy

In order to understand the superplasticity of Ti-15-3 alloy,superplastic behaviors of Ti-15-3 alloy with different status were investigated at 700～800 ℃ and strain rates ranging from 1×10-4s-1 to 3×10-3s-1.The results show that the alloys exhibit good superplasticity.The elongation of all the cold rolled sheet is better than that of the solution treated sheet under the same deformation conditions,and it increases with the increasing of the cold rolled strain of the sheet.The largest elongation and strain rate sensitivity exponent are gained at 780 ℃,and this temperature is the optimal deformation temperature of this alloy.52% cold rolled sheet gets the largest elongation of 370% in the condition of 780 ℃ and 1×10-4s-1,and m is 0.56.Deformation temperature and strain rate affect the superplasticity of Ti-15-3 alloy severely.The elongation of this alloy increases with the increasing of temperature and the descending of strain rate at 730～780 ℃,but flow stress descends.