Structural evolution of titanium powder during ball milling in different atmospheres

Structural evolution of titanium powder during ball milling (BM) in different atmospheres was studied. Structural characterization of the as-milled and annealed specimens was carried out by means of X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), as well as energy dispersive X-ray spectroscopy (EDS). Experimental results show that the milling atmosphere has a strong influence on the structural evolution of Ti powder. TiN was synthesized by milling Ti powder in N2 or NH3 atmosphere. Different products were obtained by milling Ti powder in air in different conditions. Titanium oxynitride, which has the same crystal structure as that of TiN, was formed in closed vials. Titanium oxide and titanium oxynitride, however, were produced in open vials. Discussion on the formation of titanium oxide and titanium oxynitride during ball milling in different atmospheres is presented in this paper