SiB_(4)高温热氧化机理及动力学  

Thermal Oxidation Mechanism and Kinetics of SiB_(4) at Elevated Temperature

作　　者：孙宇雷 李明伟[1] 张庆猛 杨志民 钟业盛[2] 史丽萍[2] 赫晓东[2,4] Sun Yulei;Li Mingwei;Zhang Qingmeng;Yang Zhimin;Zhong Yesheng;Shi Liping;He Xiaodong(National Key Laboratory for Precision Hot Processing of Metals,Harbin Institute of Technology,Harbin 150001,China;Center for Composite Materials and Structure,Harbin Institute of Technology,Harbin 150080,China;Advanced Electronic Materials Institute,GRIMAT Engineering Institute Co.,Ltd,Beijing 100088,China;Shenzhen STRONG Advanced Materials Research Institute Co.,Ltd,Guangdong 518000,China)

机构地区：[1]哈尔滨工业大学金属精密热加工国家级重点实验室,黑龙江哈尔滨150001 [2]哈尔滨工业大学复合材料与结构研究所,黑龙江哈尔滨150080 [3]有研工程技术研究院有限公司先进电子材料事业部,北京100088 [4]深圳烯创先进材料研究院有限公司,广东深圳518000

出　　处：《稀有金属材料与工程》2022年第7期2662-2666,共5页Rare Metal Materials and Engineering

基　　金：深圳市科技计划项目(KQTD2016112814303055)。

摘　　要：本工作以高超声速飞行器表面高发射率涂层关键填料Si B_(4)为研究对象,采用非等温热重分析法在空气条件下对粒径40μmSiB_(4)粉体高温热氧化过程以及氧化动力学进行研究。结果表明,SiB_(4)热氧化起始温度为650℃,热氧化过程质量呈现恒重→增重→恒重变化趋势,其中高温区试样恒重分别是由玻璃相包覆保护作用、氧化增重与气相挥发损失竞争作用2种机制控制。升温速率对Si B_(4)热氧化过程影响显著,升温速率越快,放热效应越明显。SiB的平均活化能为239.14 kJ/mol,动力学指前因子A=9.8696×10^(9)s^(-1),热氧化动力学函数为G(α)=ln[–ln(1–α)]^(1.7574)。In this work, the high-temperature thermal oxidation process and kinetics of SiBpowder(particle size~40 μm), which is usually applied as key filler for high-emissivity coating on the surface of hypersonic vehicle, were investigated by non-isothermal thermogravimetric analysis under air condition. The results show that the thermal oxidation of SiBstarts at 650 ℃, and their mass along the thermal oxidation process shows a trend of constant mass → mass gaining → constant mass. The second constant mass stage occurring at high-temperature region is controlled by two mechanisms, namely, the protective effect of glass encapsulation and the competitive effect of oxidation mass gaining and volatilization of gas species. The heating rate has a significant effect on SiBoxidation process, and the faster temperature rises, the more obvious exothermic effect is.The average active energy of SiBpowder is 239.14 k J/mol. The kinetic preexponential factor is 9.8696×10^(9) s^(-1). The conversion function of oxidation reaction of SiBis G(α)=ln[–ln(1–α)]^(1.7574).

关 键 词：高发射率涂层填料 SiB_(4) 热氧化机理 热氧化动力学 

分 类 号：V254.2[一般工业技术—材料科学与工程]