Preparation of Ti+Ti6Si2B powders by high-energy ball milling and subsequent heat treatment

The present work reports on the preparation of two-phase TiSS+Ti6Si2B alloys by high-energy milling and subsequent heat treatment. The milled and heat-treated products were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and microanalysis via WDS. Results indicated the dissolution of silicon and boron atoms into the Ti lattice to form supersaturated solid solutions during the ball milling of Ti–10Si–5B and Ti–20Si–10B powders. TiB2 precipitates were formed during ball milling, and the metastable structures were decomposed due to the released heat from its exothermic formation. After heat treatment at 1100 °C for 4 h, the equilibrium microstructures of the Ti–10Si–5B and Ti–20Si–10B alloys indicated the majority presence of the Ti and Ti6Si2B phases. TiB precipitates were found in Ti–10Si–5B and Ti–20Si–10B powders after heat treatment at 1200 °C for 16 h, indicating that the composition was moved from two-phase Ti+Ti6Si2B region to the three-phase Ti+Ti6Si2B+TiB field.