Abstract:
With the pulse current of 50 A, 53 A, 57 A and 60 A, the equilibrium initial temperature of 700 ℃, 800 ℃,900 ℃ and 1000 ℃ was obtained respectively. With different strain rates, the electrothermal stretching test of Ti
2AlNb was carried out. By comparing, the mechanical properties and microstructure of Ti
2AlNb under the original state and different current states were analyzed. The results show that the mechanical properties of Ti
2AlNb gradually decrease with the increase of current and the decrease of strain rate. When the initial current is 50 A, 53 A and 57 A, the fracture mode of the sample is plastic fracture, showing microporous aggregation type. The failure mode under other loading current(initial temperature) and strain rate is fusing. As the loading current(initial temperature) increases, the O phase and α
2 phase decrease sharply. The α
2 phase decrease makes the binding effect on B
2/β phase weaken, and the B
2/β phase continuously grows. The decrease of strain rate is also associated with the decrease of O phase and α
2 phase content and the increase of B
2/β phase, which is essentially due to the effect of temperature.