Transition metal carbide and boride through alkoxide gelation

Fine powders of transition metal carbides (Tic, ZrC) were synthesized by hydrolyzing metal alkoxides in carbon suspensions and subsequently heating in vacuum. Mixing of carbon and hydrated metal oxide was strongly affected by the pH of the solution, the hydrolysis rate, and the property of carbon. The heat treatment of the mixture gave a soft agglomerate of the carbide, which was ultrasonically crushed into submicron–sized powder of near monodispersion. An intimate mixture of ZrC and ZrB2 was also obtained in the same manner by adding triethylborate to the starting solution. Fine aggregates and ultrasonically separated particles were analyzed by EPMA and microdiffraction.