Research On The High Temperature Constitutive Equations Of Ti₂AlNb-Based Intermetallic Compound

2Ti AlNb based alloy was a intermetallic compound materials developed in the early 1990 s O phase 2Ti AlNb based alloy have high specific strength, rigidity, creep resistance and low density. This paper is mainly based on Ti ?22 Al ?25Nb alloy tensile testing and high temperature constitutive relation.The tensile tests of Ti ?22 Al ?25Nb are investigated at the temperature range of 25 ~ 700 oC and strain rate of 310 / s?and 410 / s?to get the true stress-strain data and yield strength, elastic modulus and other material properties of the material. Analyze material properties with change in temperature and strain rate. The results show that the mechanical property has great influence on temperature change. Strain rate change has affected weakly as compare with the other parameters. It has good plasticity during the temperature range of 25 ~ 700 oC.The SEM observation reveal that the fracture is transgranular cracking.Based on the experimental results, application of J-C and Z-A macroscopic constitutive model characterization of plastic deformation in the process of true stress-strain constitutive equation. And aiming at the effects of temperature on mechanical properties of the2 Ti AlNb based alloy, modify the J-C and Z-A model. Comparing modified J-C and Z-A model predict results with the test results, the results show that the two models could accurately predict the metal plastic deformation behavior. Come up with a method to build a complete stress-strain constitutive relation. The method is relatively simple and higher prediction precision.Using modified J-C model to predict the IC10 alloy stress-strain curves over the range of 25 ~ 700 oC, and predict the Ti Al based alloy stress-strain curves over the range of 25 ~ 780 oC. Comparing the predict results with the test results, it shows that the modified J-C model is simple, less parameters, high prediction and wide applicability.