浮上式流動層CVDによるTiN-Al_2O_3系複合粉末の合成

A TiN-Al_2O_3 composite powder was synthesized by the floating-type fluidized- bed CVD. Al_2O_3 particles were floated in an N_2/NH_3 gas mixture, and TiCl_4 was fed to deposit TiN. The composite powders obtained and the ceramics were examined by an electron probe microanalyzer (EPMA). The TiN content in the composite powder was controlled by the flow rate of carrier gas of TiCl_4. It was deduced that the composite powder was formed by deposition of fine TiN particles onto Al_2O_3 particle surfaces, aggregating to about 3μm. Ceramic from the composite powder containing 12.5 wt% TiN was conductive. Its microstructure suggested that TiN was uniformly dispersed as compared with mechanical mixing.