Research on mechanical alloying and sintering of TiC/Ti powders

摘要

In order to improve the sintering activity of TiC which was usually added into the binder of polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN), the powders of TiC and Ti mixed as molar ratio of TiC:Ti=1:0.3 were treated by mechanical alloying. The structure and the morphology of the milled powders were analyzed by X-ray diffraction (XRD) and scan electron microscope (SEM),respectively. The milled powders were sintered by cubic hinge press. The structure of the sintered sample was analyzed by X-ray diffraction and the hardness was tested. The results showed that the grain size of the TiC and the Ti powders were decreased, as the milling time increased, and the nonstoichiometric compound of TiCx was formed. The sintering activity of the TiC/Ti powders treated by mechanical alloying increased greatly. The hardness of the sintered sample improved from 829.2 HV for the raw powders to 2587.37 HV for the powders mechanical alloyed 20 hours.