石墨电极表面氩弧熔覆原位合成ZrB<sub>2</sub>-SiC/Si 抗氧化涂层

石墨电极表面氩弧熔覆原位合成ZrB₂-SiC/Si 抗氧化涂层

摘要: 为了增强石墨在高温条件下的抗氧化性,采用氩弧熔覆技术,以硅粉、锆粉和B₄C粉为原料在石墨电极表面制备原位合成ZrB₂-SiC/Si抗氧化涂层.利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)对涂层进行组织分析和物相分析,并对涂层的抗氧化性能进行了测试和研究.结果表明,涂层由ZrB₂,SiC和Si组成,高温下氧化生成ZrO₂和SiO₂,阻止涂层材料进一步的氧化.抗氧化涂层与石墨基体结合良好,无气孔裂纹等缺陷,涂层中竹节状的ZrB₂枝晶与颗粒状的SiC分布均匀,在1500℃条件下灼烧10 h,氧化失重仅为0.72%.

Abstract: In order to improve the high temperature oxidation resistance of graphite, ZrB₂/SiC composite coating was fabricated on the surface of graphite electrode by argon arc cladding using the Si, Zr and B₄C blended powders. The microstructure and phase composition of the clad layer were researched by using scanning electron microscopy(SEM) and X-ray diffraction analysis(XRD). The result shows that the coating consisted of ZrB₂, SiC and Si. ZrO₂ and SiO₂ were formed under high temperature which prevent further oxidation of the coating.The bonding of the cladding layer and the graphite matrix was good with a continuous interface without visible defects.The bamboo like ZrB₂ and granular SiC were uniform distributed in the coating. After burning 10h at 1500℃, the oxidation weight loss rate is 0.72%.