Hot deformation behavior and dynamic recrystallization mechanisms of a novel biomedical Ti₅₄Nb₁₄Zr₁₅Mo₁₇ alloy

The Ti₅₄Nb₁₄Zr₁₅Mo₁₇ alloy with a low compressive modulus (57 GPa) has been developed with great potential for application in biomedicine. Thermomechanical treatment is one of the most important methods for optimizing mechanical properties and fabricating components. Here, we investigated the hot deformation behavior and the dynamic recrystallization (DRX) mechanisms of the Ti₅₄Nb₁₄Zr₁₅Mo₁₇ alloy during hot compression at temperatures ranging from 950 ℃ to 1100 ℃ with a strain rate of 0.001 s⁻¹ to 1 s⁻¹. The hot processing map indicated that the peak efficiency of power dissipation (_η) occurred at 1100 °C with a strain rate of 0.001 s⁻¹, during which significant DRX phenomena were observed. Two distinct DRX mechanisms were identified: continuous dynamic recrystallization, characterized by the progressive rotation of sub-grains, and discontinuous dynamic recrystallization, involving original grain boundary bulging and nucleation. The compressive yield strength and ductility of the alloy after hot deformation with the optimal hot processing parameters improved to 1197 MPa and 50 %, respectively; fortunately, the compressive modulus remained constant. And the high yield strength and ductility are superior to other biomedical Ti-alloys reported in the past five years. The present study conducted a more in-depth investigation of the application and reliability of the hot processing map of the Ti₅₄Nb₁₄Zr₁₅Mo₁₇ alloy.