DESIGN OF LOW ELASTIC MODULUS Ti-Nb-Zr ALLOYS FOR IMPLANT MATERIALS

Titanium alloys are expected to be much more widely used for hard tissue implant materials due to their superior biocompatibility and high corrosion. However, the larger Young's modulus of present titanium alloys always leads to stress shielding and harmful effects on human bones and results in premature failure of the implant. Recently a d-electron alloy design method has been proposed to design low elastic modulus titanium alloys and achieve some actual results. In this paper, a series of the Ti-Nb-Zr alloys has been designed with the d-electron alloy design method, and the phase structure, lattice parameter and elastic modulus have been investigated. The results show that with the increase of and , the lattice parameters of these alloys increase monotonously with the single phase structure of bcc β phase. The maximum increment reaches 4.5% compared with that of matrix β phase. As the and increase up further, the phase structure begins to change from bcc β phase to hcp α phase. Correspondingly the elastic modulus decreases first and then increase, from 96.8 GPa to 67.4 GPa, and then to 83.2GPa with the increase of and . The lattice parameter and phase structure both exhibit significant influences on the elastic modulus of these alloys.