Microstructural changes of (Ti,W)C solid solution induced by ball milling

The effect of ball milling on microstructural change of (Ti,W)C solid solution was investigated. In addition to the particle size reduction with milling time, detailed studies using the X-ray diffraction line profiles were carried out to evaluate the microstructural parameters, including lattice parameter, crystallite size and microstrain. Nelson-Riley extrapolation and Williamson-Hall method are employed. The results suggest lattice expansion, with the lattice parameter increasing from 4.3212 Ǻ to 4.3241 Ǻ. The defects and surface stress generated during ball milling are deemed to be responsible for the increased d-spacing of (Ti,W)C solid solution with milling time. The crystallite size displays a diminishing trend with increasing milling time, which is consistent with the SEM observation. However, the microstrain developed is tensile in nature and firstly increases with up to 36 h milling, and then the strain reduces for further milling perhaps due to the strain relaxation by the formation of dislocations.