Microstructural evolution during hot and cold deformation of Ti-36Nb-2Ta-3Zr-0.35O alloy
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. State Key Laboratory of Porous Metal Materials,
Northwestern Institute of Nonferrous Metals Research, Xi’an 710012, China)
2. State Key Laboratory of Porous Metal Materials,
Northwestern Institute of Nonferrous Metals Research, Xi’an 710012, China)
Abstract: The Ti-36Nb-2Ta-3Zr-0.35O (mass fraction, %) (TNTZO) alloy was produced by cold isostatic pressing and sintering from elemental powders, followed by hot and cold deformation. The effects of deformation process on microstructures and mechanical properties were investigated using the SEM, TEM, OM and the universal material testing machine. Results show that the alloy can be easily hot forged and cold swaged due to the fine-grained microstructure. Only after cold swaging by 85%, the alloy shows the typical “marble-like” structure. And the cold deformation is accompanied by stress-induced α" phase transformations. Moreover, both the strength and the ductility of the alloy are significantly improved by hot and cold working.
Key words: gum metal; hot forge; cold swage; microstructure; dislocation-free; stress-induced martensitic transformation