The aims of this work were to produce nanocrystalline powder by mechanical alloying of Co–W–Si powder mixture in a high energy ball mill and to study the phase transformation that took place during 30 h milling time. The phase constituents of the product were evaluated by X-ray diffraction (XRD). The morphological evolution during mechanical alloying was analyzed using scanning electron microscopy. The results showed that high energy ball milling, as performed in the present work, led to the formation of a Co(W,Si) solid solution and an WSi2 both of which phases were nanocrystalline. Subsequently, the 10 and 30 h milled powders were analyzed by DTA. The XRD investigations of the powders revealed that after DTA analyzing, no phase changed, except for the ordering of Co(W,Si), i.e. formation of CoWSi intermetallic compound, during the DTA analysis
