Thermodynamic Calculation and Experimental Study on TiC_xN_1-x Prepared by Carbothermal Reduction-nitridation of Ilmenite

In this study,the phase evolution and C content of the products during synthesis of TiC_xN_1-x by carbothermal reduction-nitridation in a vacuum furnace using ilmenite,coke powder and high purity nitrogen as raw materials were investigated via thermodynamic calculations and experiments.The phase evolution during the carbothermal reduction-nitridation process was analyzed by HSC thermodynamic calculation software.Based on the thermodynamic calculations,experiments at different reaction temperatures were carried out.The products were characterized by XRD and SEM-EDS,respectively.The results indicate that the formation of TiN and TiC is respectively controlled by the procedure of Ti₃O₅→TiN and Ti₃O₅→TiC,with the evolution temperature at 1 231 and 1 319 ℃,respectively.The experimental results show that TiC_xN_1-x can be initially generated at 1 200 ℃,moreover,the single phase of TiN and TiC could not be generated during the whole heating process.The C content of TiC_xN_1-x gradually increases with increase of temperature,from 9.8% at 1 200 ℃ to 36.273% at 1 350 ℃.Meanwhile,the mass fraction of N in TiC_xN_1-x decreases from 42.14% to 18.456% with temperature increasing from 1 200 to 1 350 ℃.