Metal injection moulding was applied to fabricate Ti-22Nb alloy as a low modulus material for biomedical applications. Tensile test specimens were injection moulded, followed by debinding and sintering. Sintering was at 1500℃ for 4 h under vacuum (10~(-3) Pa). Selected as-sintered Ti-22Nb samples were hot isostatically pressed at 915℃/ 100 MPa for 2 h. The nature of the titanium carbide precipitates in the as-sintered Ti-22Nb alloy was investigated. Selected area electron diffraction patterns revealed that the carbides are Ti_2C with a fcc structure. The calculation of the phase diagram showed a significant decrease of carbon solubility in Ti-22Nb compared with that in Ti from 500 to 1500 ℃, contributing to the carbide precipitation in Ti-22Nb. Due to the carbide precipitation, the as-hipped Ti-22Nb alloy exhibited higher tensile strength but lower elongation than conventionally processed Ti-22Nb.
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