放电等离子烧结制备B_4C/CeB_6复合材料

B_4C/CeB_6 Composite Ceramic Prepared by Spark Plasma Sintering

以稀土氧化物CeO_2为烧结助剂,采用放电等离子(SPS)烧结工艺制备了B_4C基复相陶瓷。研究了CeO_2添加量(质量分数,%)对B_4C基体的致密化和烧结体硬度的影响,并与纯B_4C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,CeO_2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CeB_6填充在B_4C晶粒之间,提高了制品的相对密度。当CeO_2添加量为4%时,在烧结压力35 MPa和1750℃下烧结,样品的相对密度最高(96.7%),其洛氏硬度可达到89.6(HRA)。

Dense B_4C matrix composites were synthesized by a spark plasma sintering（SPS） process using CeO_2 powder as the sintering aid.The effects of CeO_2 on densification and properties of B_4C were studied,and it was compared with the specimen without additive.X-ray diffraction and scanning electron microscopy were employed to examine the phase and micro structure of the composites,respectively.The results indicate that the addition of CeO_2 powder can significantly improve the sintering property of B_4C.The relative density of the samples increases because the generated CeB_6 between B_4C grains.The specimen with 4wt% CeO_2 sintered at 1750 ℃under 35 MPa exhibits the highest relative density of 96.7% and Rockwell hardness of 89.6.