Abstract: There is disclosed a method of producing, in large volumes and at low cost, Ta, Nb, Zr and Hf carbide, nitride or carbonitride whiskers, preferably submicron, having excellent reinforcing properties, suitable as reinforcement in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Oxides of Ta, Nb, Zr and Hf or alkali compounds thereof in an amount to satisfy the stoichiometric requirements of the desired carbide or nitride are mixed with the carbon source along with an alkali and/or alkali earth metal halogenide as a volatilization agent for the metal and a catalyst for the whisker growth such as Ni and/or Co. The reactant powders are blended in some typical manner using a high speed blender so as to intimately mix them. Finally, the starting material is subjected to nitriding, carbonizing or carbonitriding heat treatments in order to produce the desired whiskers.

Abstract: Ceramic precursor compositions, such as metal hydroxides and oxides, are electrochemically deposited in a biased electrochemical cell. The cell typically generates hydroxide ions that precipitate metallic or semimetallic ions to form insoluble solids that may be separated from the cell, then dried, calcined and sintered to form a ceramic composition.