利用反应烧结法制备多孔碳化物陶瓷

Preparation of porous carbides by reactive sintering

  • 摘要: 利用反应烧结的方法,通过甲烷碳化还原三种过渡金属氧化物(Cr2O3、TiO2和WO3)压坯,制备了其相应的多孔形态的碳化物(Cr3C2、TiC和WC)陶瓷.通过扫描电子显微镜观察检测,对反应烧结产物的表面和截面形貌进行了分析,并对这三种过渡金属碳化物的孔隙结构进行了初步的表征.通过物相分析研究了反应烧结的动力学过程,发现利用含体积分数10%甲烷的混合气体碳化还原制备多孔TiC和WC陶瓷的起始温度分别为1200℃和1000℃,低于这两个温度时发生其他相变,有其他中间产物生成.利用反应烧结的方法制备多孔Cr3C2陶瓷时,反应烧结温度越高,碳化铬陶瓷的骨架和孔隙平均尺寸越大.

     

    Abstract: Three porous carbide ceramics (Cr3C2, TiC and WC) were successfully prepared through a reactive sintering process by reducing their oxides (Cr2O3, TiO2 and WO3) with methane. The surface and cross section morphologies of sintered products were examined by scanning electron microscopy, the microstruetures were characterized, and the reaction dynamics was studied by X-ray diffraction analysis. It is found that the preparation temperatures of porous TiC and WC ceramics should he 1200℃ and 1000℃, respectively, below which intermediates will be produced in the sintering process. The average sizes of both the ceramic struts and pores for porous Cr3C2 ceramics prepared by reactive sintering increase with an increase in sintering temperature.

     

/

返回文章
返回