Characteristics of Ultrafine (Ti,W)C Solid Solution Powders Synthesized by Mechanical Milling and Subsequent Carbothermal Reduction Reaction

摘要

(Ti,W)C solid solution powders with different W contents were prepared by milling a mixture of graphite and oxides and subsequent reducing them ranging from 1100 to 1300 ℃ for 2 h.Morphology and phases of the milled and reduced powders was investigated by scanning electron microscopy (SEM),transmission electron microscope (TEM) and X-ray diffraction (XRD) analysis respectively.The reduced powders at 1300 ℃ were monolithic (Ti,W)C solid solutions when W/Ti weight ratio was less than 1.5.The diffraction peak intensity ratio of (111) to (200) plane increased apparently with increasing tungsten content which was attributed to the bigger X-ray scattering factor of W than that of Ti.The lattice parameter and average agglomerate size of (Ti,W)C solid solution powders decreased with increasing tungsten content,and their crystallites size distribution was about 50-92 nm.