氩弧熔覆原位合成TiC-TiB_2复合抗氧化涂层

In-situ synthesis of TiC-TiB_2 anti-oxidation composite layer by argon arc cladding

为了提高石墨电极的高温抗氧化性能,以钛粉和B4C粉为原料,采用氩弧熔覆技术在石墨电极表面原位反应合成TiC-TiB_2复合涂层.利用X射线衍射分析、蔡司电子显微镜和扫描电子显微镜对涂层的组织形貌和物相组成进行了分析,利用间歇法测试了TiC-TiB_2复合涂层的高温抗氧化性能.结果表明,熔覆层由花瓣状的TiC颗粒和棒状的TiB_2颗粒组成,熔覆层与石墨基体热匹配性好,表面无裂纹和气孔等缺陷,且熔覆层具有良好的抗高温氧化性能,1300℃高温氧化6h,氧化增重率为0.546mg/mm^2·h^(-1).

TiC-TiB_2 composite layer was in situ synthesized on the surface of graphite electrode by argon arc cladding technology with Si and B4 C powders as raw materials,in order to improve the high-temperature anti-oxidation property of graphite.The tissue morphology and phase composition were analyzed with scanning electron microscopy,Zeiss electron microscope and Xray diffraction,respectively. The high temperature anti-oxidation property of TiC-TiB_2 composite layer was examined by intermittent method. The results show that the cladding layer was composed of petal-shaped TiC phase and rod-shaped TiB_2 phase. The cladding layer and graphite substrate had good thermal compati-bility,and no defects such as surface cracks or pores happened.The cladding layer had good high-temperature anti-oxidation property. The oxidation rate of weight gains was only 0. 546 mg·mm-2h-1after oxidized at 1 300 ℃ for 6 h.