Ti52Al48 and Ti62.5Si37.5 alloys were synthesised by mechanical alloying (MA) from blended powders of titanium, aluminium and silicon, and then coated with Al and Ti by magnetron sputtering. The phase transformations occurred during milling were followed by X-ray diffraction (XRD) analysis. Scanning calorimetry (DSC) was used to study the thermal behaviour of the powders, with and without metallic coating, up to 1000degreesC. After 50h milling the Ti52Al48 alloy was formed mainly by Ti(Al) + Ti3Al. The Ti5Si3 intermetallic was present in the final structure of the milled Ti62.5Si37.5 alloy. During heating, gamma-TiAl + Ti3Al and Ti5Si3 are formed in powders core for the Ti-Al and Ti-Si systems, respectively. Al-coating showed a higher ability to react with the powders to form intermetallics than Ti-coating. In the first case, the Ti3Al, gamma-TiAl and TiAl3 phases were detected at the powders surface. Ti-coating was stable up to high temperatures. No reaction of this element with the powders was observed.