Synthesis of Ultrafine TiC-5%Co Powder by Using Co Nitrate and TiO(OH)2 Slurry and Evaluation of Sintered Materials Prepared by Mixing WC-Co

Ultrafine TiC-5%Co powders were synthesized by spray drying of aqueous solution of TiO$(OH)_2$ slurry and cobalt nitrate, followed by calcination and carbothermal reaction. The oxide powders with carbon powder was reduced and carburized at $900^{\circ}C{\sim}1250^{\circ}C$ under hydrogen atmosphere. During reduction, CO gas was mainly evolved by reducing reaction of oxides. Ultrafine TiC-5%Co powders were easily formed by carbothermal reaction at $1250^{\circ}C$ due to using ultrafine powders as raw materials. The ultrafine WC-TiC-Co alloy prepared by sintering of mixed powder of ultrafine WC-13%Co powder and ultrafine TiC-5%Co powder has higher sintered density and mechanical properties than WC-TiC-Co alloy prepared by commercial WC, TiC and Co powders.

Co 질산염과 TiO(OH)2 슬러리를 이용한 초미립 TiC-5%Co 제조 및 WC-Co 분말과의 혼합에 따른 소결체 특성