Theoretical consideration on composite oxide scales and coatings  

作　　者：何业东 高唯 

机构地区：[1]Beijing Key Laboratory for Corrosion-Erosion and Surface Technology,University of Science and Technology Beijing [2]Engineering School,The University of Auckland

出　　处：《Journal of Rare Earths》2013年第5期435-440,共6页稀土学报（英文版）

基　　金：supported by National Natural Science Foundation of China(51071030)

摘　　要：The present paper discussed some fundamental aspects on composite oxide scales and coatings for protection of alloys from high temperature oxidation, the related thermodynamic conditions, special mechanical characteristics and a sealing mechanism. It was proposed that the oxide scales and coatings with a composite structure should possess superior mechanical properties than that with a single phase oxide. It also showed that the A1203 scales or coatings doped with 3（203 and ZrO2 （or YSZ）-A1203 composite coatings possessed superior properties at high temperatures. In such composite oxide scales and coatings, the fracture resistance of the scales was increased by the toughening effect, the thermal stress was decreased owing to the increase of thermal-expansion coefficients, and A1203 phase could seal the alloy substrate well In addition, the kinetic equation of thermal growth oxide on alloy covered with composite oxide coatings was derived.The present paper discussed some fundamental aspects on composite oxide scales and coatings for protection of alloys from high temperature oxidation, the related thermodynamic conditions, special mechanical characteristics and a sealing mechanism. It was proposed that the oxide scales and coatings with a composite structure should possess superior mechanical properties than that with a single phase oxide. It also showed that the A1203 scales or coatings doped with 3（203 and ZrO2 （or YSZ）-A1203 composite coatings possessed superior properties at high temperatures. In such composite oxide scales and coatings, the fracture resistance of the scales was increased by the toughening effect, the thermal stress was decreased owing to the increase of thermal-expansion coefficients, and A1203 phase could seal the alloy substrate well In addition, the kinetic equation of thermal growth oxide on alloy covered with composite oxide coatings was derived.

关 键 词：rare earth oxides composite oxide scales composite oxide coatings high-temperature oxidation of alloys 

分 类 号：TG174.44[金属学及工艺—金属表面处理]