Abstract
The reactive sintered compacts of Ti-W-Cr-B mixed powders were manufactured by a pulse electric current technique. Identification and characterization of the resulting boride phase were done using EPMA, XRD and other methods.
The density of the sintered compacts rose rapidly with sintering temperature up to 1773 K, at which temperature the relative density was 94%. Above this temperature, the density rose only slightly with increasing sintering temperature. The borides of Ti and W were synthesized from mixed metal powders by this method. The type of boride formed and its composition depended on sintering temperature. Compacts sintered at lower temperatures consisted of WB2 and TiB2 phases, but at the highest sintering temperature, 2173 K, the main phase was (Ti, W, Cr)B2 solid solution, in which W and Cr were dissolved in TiB2. There was also a very small amount of β-(W, Ti, Cr)B phase. By annealing compact sintered at high temperature, the (Ti, W, Cr)B2 solid solution phase decomposed and the amount decreased.
