Preparation of TiC powders by carbothermal reduction method in vacuum

真空碳热还原法制备碳化钛粉末(英文)

The preparation of fine TiC powders by carbothermal reduction of TiO2 in vacuum was investigated by XRD,SEM,XRF and laser particle sizer.Thermodynamic analysis indicates that it is easy to prepare TiC in vacuum and the formation sequence of products are Ti4O7（Magneli phase）,Ti3O5,Ti2O3,TiCxO1-x and TiC with the increase of reaction temperature.Experimental results demonstrate that TiC powders with single phase are obtained with molar ratio of TiO2 to C ranging from 1：3.2 to 1：6 at 1 550 ℃ for 4 h when the system pressure is 50 Pa,and TiC1.0 is gained when the molar ratio of TiO2 to C is 1：4 and 1：5.In addition,fine TiC1.0 powders（D50 equals 3.04 μm） with single phase and low impurities are obtained when the molar ratio of TiO2 to C is 1：4.SEM observation shows that uniform shape,low agglomeration,and loose structure are observed on the surface of block product.

采用XRD、SEM、XRF以及激光粒度分析仪等分析手段,研究真空条件下碳热还原TiO2制备的碳化钛粉末。热力学计算和实验结果表明:真空条件下容易获得碳化钛,且随温度逐渐升高得到的产物顺序为:Magneli相(Ti4O7)、Ti3O5、Ti2O3、TiCxO1-x和TiC。当物料配比为1:3.2-1:6时,在1550℃保温4h的条件下可获得单相TiC粉末;物料配比为1:4和1:5时,产物粉末为标准化学计量的TiC1.0粉末;物料配比为1:4时,得到的产物为单相低杂质超细碳化钛粉末(D50为3.04μm)、SEM观察表明在产物块体表面存在分布均匀、团聚小、结构疏松的结构。