摘要
采用硅作为烧结助剂热压烧结SiC陶瓷，用扫描电镜、X射线衍射仪和热重分析仪研究了不同状态SiC陶瓷的氧化性能。结果表明：未预处理SiC在等温氧化过程中，600--1100℃区间内，等温氧化动力学曲线服从抛物线规律；而在1100～1300℃区间，则偏离了抛物线规律，氧化速率随温度的升高先增大后减小。经过高温预氧化处理之后，SiC试样在等温氧化过程中，氧化动力学曲线为直线，较未预处理试样氧化增重显著减少；连续升温氧化过程中，和未预处理试样相比，剧烈氧化开始温度升高，同时其氧化速率及最终的氧化增重均大幅度降低。说明了高温预氧化处理能够有效提高SiC陶瓷的抗氧化性能。
SiC ceramic was prepared by hot-pressing method with Si as an additive. XRD, SEM, isothermal oxidation-weight gain and non-isothermal oxidation （TG） were used to study the oxidation properties of SiC. The results show that the kinetics of isothermal oxidation without pre-oxidation SiC obey a parabolic rule at 600--1 100 ℃, and the oxidation speed of SiC increased at first and then decrease with temperature increasing at 1 100--1 300℃. After pre-oxidation process, the kinetics of isothermal oxidation of SiC obey a linear rule in the whole experimental temperature range. The sample has a higher severe oxidation temperature than the origin sample in the non-isothermal condition. The weight gain of SiC after pre-oxidation is less than that of the origin sample remarkably. The pre-oxidation process is a useful method to improve the oxidation resistance of SiC ceramic.
出处
《机械工程材料》
CAS
CSCD
北大核心
2007年第9期11-14,共4页
Materials For Mechanical Engineering
关键词
SIC陶瓷
等温氧化
非等温氧化
SiC ceramic
isothermal oxidation
non-isothermal oxidation
