Study on Microstructure and Mechanical Behavior of Solution Treated Ti-41Nb Alloy

The microstructure and mechanical behavior of solution treated Ti-41Nb alloy were systematically investigated by optical microscope, tensile test and in situ synchrotron high-energy X-ray diffraction. The results show thatafter solution treatment at 800℃+water quenching, Ti-41Nb alloy presents a typical dual-phase structure which is characterized by exiguous lath-shaped α״martensite distributed on the equiaxed β matrix. The stress inducedmartensitic transformation (SIMT), together with elastic deformation, takes place concurrently during loading. The stress-induced martensitic transformation fromβ to α″ takes place intensively in the strain range from 0.0% to 3.3% but slightly from 3.3% to 4.0%.In the subsequent unloading process, the solution treated Ti-41Nb alloy undergoes elastic recovery, accompanied by the reverse martensitic transformation from α″to β. After unloading, alarge amount of α″ martensiteis not transformed into βparent phase, which results in a residual strain of 2.9% in the alloy. © 2021, Science Press. All right reserved.