Synthesis of β-Sialon/Ti(C,N) Composites Using Low and Middle Grade Bauxite and Ilmenite by Carbothermal Reduction-Nitridation
β-Sialon/Ti(C,N) composites were prepared using low and middle grade bauxite and ilmenite as raw material,while coke as reducing agent in high purity nitrogen atmosphere through carbothermal reduction-nitridation(CRN).The main phases of low and middle grade bauxite are kaolinire(Al2O3·2SiO2·2H2O) and (Al2O3·H2O)2 and ilmenite mainly contain ilmenite(FeTiO3) and rutile(TiO2).The reaction products of bauxite are the β-Sialon(Z=3,Si3Al3O3N5) while those of ilmenite are TiC and Fe.The results showed that the main phases are β-Sialon,Ti(C,N),Al2O3 and Fe when the reaction temperature is at 1400℃ holding for 4 hours (10wt% ilmenite and 90wt% bauxite as raw material).However,β-Sialon decomposes into 21R at 1450℃ and into 15R and AlN at 1500℃.So 1400℃ is selected as the proper temperature to synthesize β-Sialon/Ti(C,N) composites.At 1400℃,the β-Sialon crystals with the largest quantity grow well and show long column in shape.With the increase of the reaction temperature β-Sialon begins to decompose,the β-Sialon crystals change to short columnar,with the number decreasing quickly.
β-Sialon Ti(C,N) CRN Composites Bauxite Ilmenite
Dexin Yang Yangai Liu Dingyun Ye Zhaohui Huang Minghao Fang Yongbo Chen Jianxin Shen Baochen Wang
School of Materials Science and Technology,China University of Geosciences,Beijing 10083,China
国际会议
桂林
英文
112-116
2012-07-16（万方平台首次上网日期，不代表论文的发表时间）