高纯超细碳化钛粉体制备

Preparation of high purity ultrafine titanium carbide powder

碳化钛(TiC)具有高熔点、超高硬度、良好的高温强度和化学稳定性等特点,广泛应用于刀具、磨料、涂层材料及复合材料的增强体等,在结构陶瓷中占有重要的地位。本研究采用碳热还原结合金属钙处理的方法,解决了在碳热还原TiO_(2)合成TiC的过程中,碳添加量难以控制、产物中游离碳含量较高的问题。主要研究钙配比、钙处理温度及处理时间对钙处理过程的影响。结果表明,当温度为1250℃、钙配比为1、钙处理时间为4 h时,制备出了高纯超细TiC粉体。金属钙作为脱碳剂和脱氧剂,提高了TiC粉体的纯度。此外,高温与高钙配比使TiC颗粒粒径明显增大,颗粒形貌呈立方体结构。

TiC has the characteristics of a high melting point,ultrahigh hardness,good high-temperature strength and chemical stability,which makes it important in structural ceramics.At present,TiC is widely used in cutting tools,abrasives,coating materials and reinforcements of composite materials.In this study,an approach of carbothermic reduction combined with metal calcium treatment was employed to solve the problems of preparing TiC by carbothermic reduction of TiO_2,such as inaccurate carbon addition and higher free carbon content.This study scrutinized the influences of calcium treatment parameters from calcium ratio,treatment temperature and time.The results show that the high-purity ultrafine TiC powder is prepared by treating the metal calcium with a mass ratio of one time at 1 250 ℃ for 4 h,and the metal calcium as a decarbonization agent and deoxidizer improves the purity of TiC powder.In addition,a high temperature and calcium ratio can not only significantly increase the particle size of TiC powder but also obtain a cubic particle morphology.