Investigation of mechanical properties of TB2 alloy at cryogenic temperature

The tensile and impact properties of solution-treated and aged TB2 alloy at temperatures ranging from 77 K to 293 K have been studied by means of tension test and pendulum impact-test, and fracture features of the tested samples were examined by scanning electron micro scope (SEM). The results indicate that with decreasing test temperature, the ultimate strength and yield strength of TB2 alloy increases, while the elongation decreases monotonously and the impact absorbing energy reduces gradually. The tensile fracture surface of the solution-treated samples displayed inter-crystalline and dimple fracture characteristics, and more inter-crystalline features with decreasing tension temperature. While the solution-treated TB2 alloy impact samples displayed dimple fracture features at 293 K, quasi-cleavage and dimple fracture at 223 K, inter-crystalline and dimple fracture at 198 K, inter-crystalline and dimple fracture accompanied with secondary cracks at 173 K, and cleavage inter-crystalline fracture at 78 K. besides the aged TB2 alloy samples exhibited ductile and brittle fracture features within the testing temperature range, and the impact samples exhibited dimple and inter-crystalline fracture with formation of tearing edges and secondary cracks.