Sintered Ti–Fe alloys with in situ synthesized TiC dispersoids

Titanium and its alloys can be strengthened by adding carbon because of the solid solution strengthening and dispersion strengthening effects. The level of strengthening depends on the source and the amount of carbon chosen. This study compares the microstructures and mechanical properties of Ti–7Fe–xC, with the carbon provided by graphite powders and two carbonyl iron powders. All sintered compacts reached relative densities of about 97%. The compacts produced using a mixture of Ti powders and OS carbonyl iron powders, which contain SiO2, had the highest tensile strength of 1007 MPa, a hardness of 34HRC, and an elongation of 10%. The microstructure shows that fine TiC and SiO2 dispersoids were uniformly distributed in the Ti–7Fe matrix, contributing to strengthening. The evolution mechanism of TiC is proposed based on the microstructure observations and Thermo-Calc calculations.