Structural-Phase Evolution during In Situ Mechanochemical Synthesis of Titanium Carbide in a Nickel Matrix

The structural and phase evolution of powders in a Ni-Ti-C ternary system with 50 wt % Ni during mechanochemical synthesis in an AGO-2 planetary ball mill was studied using X-ray diffraction analysis and scanning electron microscopy. The formation of titanium carbide in the presence of nickel was found to be accelerated, and proceeds in a mechanically stimulated reaction mode with an induction period of less than two minutes. The value of the nickel lattice parameter was observed to increase up to 0.35733 nm with increasing mechanical activation time. The products of mechanochemical synthesis, subjected to four minutes of mechanical activation, are titanium carbide, a solid solution of titanium and carbon in nickel, and iron (approximately 1 wt %, resulting from milling) with agglomerate sizes of 1-30 mu m.