Study On The Best Strain Rate Superplasticity And Application Of TA15Titanium Alloy

Titanium alloy is a very important lightweight structural material; it has good heatresistance and low temperature performance meanwhile,it has highlight advantages ofhigh specific strength and excellent corrosion resistance. TA15titanium alloy Has goodsuperplasticity, Strain rate has remarkable effect on superplasicity. Superplastic formingof titanium alloy is a new techology developed in recent years. The technique makesuse of materials has small deformation resistance in Superplastic State to ruduce theequipment tonnage The parts which has compiex shape,high precision can be disposableforming under Superplastic forming techology.TA15alloy has a narrow process window, local overheating and high resistance ofdeformation. In the research, FEM technology was adopted in simulating the isothermalforging process of airplane frame, which can provide scientific foundation for predictingwhether defects occurring or not and determining the optimal process parameters.This topic proposed the deformation theory of Optimun strain rate Superlasicity,which is based on the research of Maximum m and constant strain rate superplasticitymethods.Some subprograms were compiled under Visual Basic6.0environment for thecontrolling system of Optimun strain rate Superplasticity, the program could fulfill thetask of controlling the drawing machine, acquiring, analyzing and processing datagenerated during the experiment, And ensure calculation precisionAt the temperature of900℃, the superplastic deformation behavior of TA15alloyhas been investigated.the results showed that the best strain rate gained from theMaximum m method is reliable. TA15The best deformation prodess parameters ofTA15alloy is:=0.00026ε-1.02197，the elongation reaches2167%under this experimentcondition. Meanwhile, its elongation reaches1920%when adopted the Maximum mmethod at the same temperature.Finally, Based on the experiment, the stress-strain curves of TA15alloy duringhigh temperature deformation has been established, and the curves was integrated intothe FEM software, then a couple simulation of deformation has been carried out for theairplane frame isothermal superplastic forging and isothermal forging of TA15alloy.The effect of process parameters, including the punch velocity, on the stress and strainduring isothermal forging has been studied and load-journey curves with different parameters have been calculated. The results showed that the maximum load tonnage is18293t,2485t, isothermal superplastic forging can rudece stress useful for the strainuniform distribution...