Quantitative analyses of TiC nanopowders via mechanical alloying method

The synthesis of nanostructured TiC by mechanical alloying has been investigated in recent years; however, quantitative analysis of its activation energy and mechanical properties has seldom been performed. Thus, in this paper, the activation energy of TiC synthesis and the relationship between its mechanical properties, microstructure, and dislocation density are determined and thoroughly discussed. A mechanical alloying technique in a planetary ball mill for 15, 20, and 25 h using Ti and C as feedstocks in argon (Ar) gas was employed to prepare nano-TiC powders. TiC crystallite sizes and lattice strain were evaluated by using X-ray diffraction based on the Williamson-Hall method. The activation energy, E-a, of the as-milled powders was determined by combining differential scanning calorimetry curves with the Kissinger equation. The morphological properties, mechanical properties (hardness and Young's modulus), and the particles size distribution of the nanoceramics were examined using various techniques, including field-emission scanning electron microscope, transmission electron microscopy, nanoindentation, and atomic force microscopy. The milling time had a remarkable effect on the hardness and on Young's modulus, with particle sizes of 95.12, 80.22, and 64.18 nm after 15, 20, and 25 h of milling, respectively. Furthermore, the results revealed that the decrease in the nano-TiC roughness was associated with an increase in the milling time.