Synthesis of nanocrystalline titanium carbide alloy powders by mechanical solid state reaction

Abstract

A high-energy ball mill operated at room temperature has been used for preparing titanium carbide (TiC) alloy powders, starting from elemental titanium (Ti) and carbon (C) powders. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) have been used to follow the progress of the mechanical solid state reaction of Ti and C powders. A complete single phase of fcc-Ti44C56 alloy powders is obtained after a very short milling time (20 ks). The lattice parameter (a 0 ) of the end product of Ti44C56 was calculated to be 0.4326 nm. The presence of excess starting reactant materials (Ti and/or C atoms) in the final product of the alloy powders could not be detected. The end product of Ti44C56 alloy powders possesses homogeneous, smooth spherical shapes with an average particle diameter of less than 0.5 μm. The internal structure of the particles is marked by fine cell-like features of about 3 nm. On the basis of the results of the present study, the mechanical alloying (MA) process appears to provide a powerful tool for the fabrication of Ti44C{im56} alloy powders at room temperature. The mechanism of mechanical solid state reaction for formation of Ti44C56 alloy powders is discussed.