The Effect of Niobium Addition on Properties of Titanium-Based Alloy Fabricated via Mechanical Alloying

Abstract

The aim of this study was to investigate the effect of niobium addition on phase formation, densification, microhardness and compressive properties of Ti-Nb alloys that possess suitable characteristics as bone fixation device. The mixture of Ti and Nb powders was mechanically alloyed (MA) in a planetary mill for two hours. The effect of Nb addition to Ti was investigated by x-ray diffraction (XRD) analysis. In addition, density, microhardness and compressive behavior of the sintered alloy were also determined by the principle of Archimedes, Vickers microhardness test and compression test, respectively. The results suggested that Nb addition has changed the phase from α-Ti to β-Ti. As the Nb addition was increased from 0 wt.% to 40 wt.%, it is observed that the density of alloy increased from 4.17 g/cm3 to 5.24 g/cm3. The microhardness and compressive modulus were 306.92 HV and 57.06 GPa for Ti-0Nb (wt.%), while the mechanical properties of the alloy dropped to 218.23 HV and 25.88 GPa when the Nb addition was up to 40 wt.%. This trend is similar to the compression strength, which the compression strength for Ti-0Nb (3221 MPa) decreased to 2123 MPa as Nb was incorporated into Ti up to 40 wt.%. It is found that Ti-40Nb possess close resemblance to the Young’s modulus of human cortical bone which lies in the range of 7-30 GPa and exhibit suitable characteristics as bone fixation device.