Microstructural Evolution of Ti-Mo-Ni-C Powder by Mechanical Alloying

The microstructural evolution of (Ti,Mo)C-Ni powder by mechanical alloying of pure titanium, nickel, carbon and molybdenum as starting powder with the composition of TiC-20 Mo2C-20 Ni in mass% were investigated by X-ray diffraction (XRD) using CuK alpha radiation, field emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray spectroscopy (EDS), and transmission electron microscopy (TEM) with EDS. The powders were mixed gradually and the size of the mechanically alloyed particles was of sub-micrometer order. The TiC structure, which indicated smaller lattice constant than TiC, clearly appeared after 100 h milling time. The particles consisted of fine grains of about 5 nm size. The nickel was transformed from crystallized phase into an amorphous phase by mechanical alloying. The molybdenum was dissolved into TiC structure and Mo/Ti ratio in (Ti,Mo)C was about 3/7. [doi: 10.2320/matertrans.MRA2008280]