A new approach to the mass production of titanium carbide, nitride and carbonitride whiskers by Spouted Bed Chemical Vapor Deposition

A new approach, the Spouted Bed Chemical Vapor Deposition (SBCVD) was used for the first time for the mass production of titanium carbide, nitride and carbonitride whiskers. The product is an ingot consisting of a large number of interweaving whiskers and filling up the whole space in the reaction tube. For reaction tubes of same size, the amount of whiskers obtained by SBCVD is by an order of magnitude more than that obtained by traditional chemical vapor deposition (TCVD). The large amount of SBCVD is ascribed to the replacement of the bulk substrate by numerous metallic powders, which are floated in the vapor phase by the upward stream of the flowing gaseous reactant and encircled in the reaction zone up and down during the whole period of whisker growth, forming a spouted bed. The new method also provided direct evidence of the VLS whisker growth mechanism, and thus clarified some confusion about this mechanism.