Study On Isothermal Forging Techniques And After-forging Structure Of Superplasticity Of Titanium Alloys

TA 15 is a "α-close" Titanium alloy. The scope of its forming temperature is narrow,its local is apt to be over-hot,its forming load is high and so on ,which bring its forming many difficulties . In order to understand the deformation behavior and the effect on deformation of the TA 15 alloy during forming and to decrease wasting of time, man power and cost, some people studied on high temperature deformation and established the stress-strain curves of the TA 15 alloy during high temperature deformation by measuring flow stress which is of certain strain rate and in certain scope of deforming temperature. In the article the effects of deforming technique parameters (including deforming temperature ,deforming speed and deforming degree) on the change of inner microstructure parameters has been analyzed by using quantitative metallography and the best scope of technique parameters has been decided. The suitable thermal treatment system has been decided by quantitatively analyzing the effects of different thermal treatment systems on microstructure . At last we can decide the leading technique by using the best scope of technique parameters and the suitable thermal treatment system gained by above experiment to test a forging technique. Then the structure of the forging is examined and the property of the forging is checked carefully. The structure and the property of TA15 titanium alloy forged by above technique meet demands.