Synthesis of Al2O3/WC powder by aluminothermic
reduction and carbonization method①
reduction and carbonization method①
(Key Laboratory of Ceramic and Refractory of Hubei Province,
Wuhan University of Science and Technology, Wuhan 430081, China)
Wuhan University of Science and Technology, Wuhan 430081, China)
Abstract: Al2O3/WC powder was synthesized by means of aluminothermic reduction-carbonization with metallic Al powder, yellow tungsten oxide and carbon black or graphite as raw materials under the protection of coke granules. The effects of:Al2O3 content, temperature, C/WO3molar ratio, and atmosphere on the synthesis of :Al2O3/WC powder were studied. The results show that the relative content of WC and W2C is strongly influenced by the factors mentioned-above. Carbon black has higher reactivity than graphite. :Al2O3-WC composite is easier to obtain under the protection of coke granules than under argon atmosphere. The CO in the coke layer can easily react with tungsten to form WC and to transfer from W2C to WC.
Key words: aluminothermic reduction; carbonization; phase composition; composite; thermodynamics