放电等离子烧结制备B4C/CeB6复合材料

B4C/CeB6 Composite Ceramic Prepared by Spark Plasma Sintering Technology

摘要:

以稀土氧化物CeO2为烧结助剂，采用放电等离子(SPS)烧结工艺制备了B4C基复相陶瓷。研究了CeO2添加量对B4C基体的致密化和烧结体硬度的影响，并与纯B4C样品进行对比。借助X射线衍射和扫描电镜分析了复合材料的物相组成和微观结构。结果表明，CeO2粉体的添加可以显著提高SPS条件下碳化硼的烧结性能。生成相CeB6填充在B4C晶粒之间，提高了制品的相对密度。CeO2的添加量分别为1 wt.%、2 wt.%、4 wt.%、6 wt.%、8 wt.%，当添加量为4 wt.%时，在/35MPa下，样品的相对密度最高(96.7%)，其洛氏硬度可达到89.6HRA.

Abstract:

Dense B4C matrix composites were synthesized by spark plasma sintering (SPS) process using CeO2 powders as the sintering aid. The effects of CeO2 on densification and properties of B4C were studied, and compared those with sample without additive. X-ray diffraction and transmission electron microscopy was employed to examine the phase and microstructure of the composites respectively. The results indicate that the addition of CeO2 powder can significantly improve the sintering propertyof B4C. The relative density of samples increased because of the existence of generated CeB6 between B4C grains. CeO2 content ranged from 1 wt.% to 8 wt.%. The specimen with 4 wt.% CeO2 sintered at 1750℃under a pressure of 35 MPa exhibited relative density of 96.7% and Rockwell hardness of 90.7HRA. Key words: boron carbide; cerium hexaboride; ceriumoxide; SPS; densification