Oxidation Behaviors of C-ZrB_2-SiC Composite at 2100℃ in Air and O_2

作     者：Zhongwei Zhang Cewen Nan Jingjun Xu Zenghua Gao Meishuan Li Junshan Wang 

作者机构：State Key Laboratory of New Ceramics & Fine Processing Department of Materials Science and Engineering Tsinghua University Science and Technology on Advanced Functional Composites Laboratory Aerospace Research Institute of Materials and Processing Technology Institute of Metal Research Chinese Academy of Sciences 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2014年第30卷第12期

页      面：1223-1229页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the National Scientific Instrument and Equipment Development Project (No. 2011YQ14014504) 

主　　题：Graphite-based composite Ceramic particles Ultra-high temperature oxidation Oxide scale Oxidation mechanism 

摘      要：The oxidation behaviors of graphite and ZrB2-SiC modified graphite composite were investigated at 2100℃ in1X105 Pa air and 0.2X105 Pa O2. The oxidation tests were conducted in an induction heating furnace. The oxidation of these two materials followed the linear rate law. The determined radius loss rates of graphite and C-ZrB2-Si C at 2100℃ were 2.18X10-2and 1.05X10-2%/s in 1X105 Pa air, and 3.23X10 2 and 2.21X10 2%/s in 0.2X105 Pa O2, respectively. The incorporation of ZrB2 and SiC decreased remarkably the oxidation rate of graphite because the oxide scale formed on the sample surface during oxidation helps in reducing the exposed surface area of the underneath substrate. In two different atmospheres with the same oxygen partial pressure, both graphite and ZrB2-SiC experienced more severe oxidation at 2100℃ in0.2X105 Pa O2than in 1X105 Pa air. The oxidation rate-controlling step for graphite and ZrB2-SiC was proposed to be the inward diffusion of oxygen through the boundary layer and through the pores in the oxide scale, respectively. A model based on diffusion theory was established to discuss the effect of the total gas pressure on their oxidation behaviors.