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 degrees C to 1100 degrees C 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 (eta) occurred at 1100 degrees 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.