Synthesis of the Ti 6Si 2B compound by mechanical alloying

Abstract

The present work reports on the synthesis of Ti 6Si 2B powders by mechanical alloying from elemental Ti–22.2 at.%Si–11.1 at.%B powder mixtures. The milled powders were then heat-treated at 1100 °C for 4 h in order to attain the equilibrium microstructure. Samples were characterized by means of X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and microanalysis via EDS/WDS. Results indicated that the silicon and boron atoms were dissolved into the Ti lattice to form a supersaturated solid solution in Ti–22.2Si–11.1B powders milled for 30 h. It was noticed the formation of an amorphous phase in Ti–22.2Si–11.1B powders milled for 100 and 200 h. Thermal analysis indicated the presence of an intense exothermic peak located close to 550 °C during heating of mechanically alloyed Ti–22.2Si–11.1B powders, which was associated to the Ti 6Si 2B formation. A large amount of Ti 6Si 2B was formed in Ti–22.2Si–11.1B powders after heating at 1100 °C for 4 h.