Sintering behavior and mechanical properties of a metal injection molded Ti-Nb binary alloy as biomaterial

Sintering behavior, microstructure and mechanical properties of a Ti-16Nb alloy processed by metal injection molding (MIM) technology using elemental powders were investigated in this work by optical microscopy, X-ray diffraction (XRD), dilatometer, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). It was found that from 700 °C to 1500 °C the homogenization and densification process of MIM Ti-16Nb alloy consisted of three steps, i.e., Ti-diffusion-controlled step, Ti-Nb-diffusion step and matrix-diffusion step. Titanium carbide formation was observed in the samples sintered at 1300 °C and 1500 °C, but not in the ones sintered at 900 °C and 1100 °C. The MIM Ti-16Nb specimens sintered at 1500 °C exhibited a good combination of high tensile strength and low Young's modulus. However, the titanium carbide particles led to poor ductility.