MoSi_2 oxidation resistance coatings for Mo_5Si_3/MoSi_2 composites

作     者：YAN Jianhui XU Hongmei ZHANG Houan TANG Siwen 

作者机构：Advanced Materials Synthesis and Application Technology Laboratory Hunan University of Science and Technology Xiangtan 411201 China 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2009年第28卷第4期

页      面：418-422页

核心收录：

学科分类：081702[工学-化学工艺] 0806[工学-冶金工程] 08[工学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0702[理学-物理学] 

主　　题：oxidation resistance coatings composites molybdenum disilicide 

摘      要：In order to improve the oxidation resistance properties of 30 at.% Mo5Si3/MoSi2 composite at high temperature in air, a molybdenum disilicide coating was prepared on its surface by a molten salt technology. XRD and SEM analysis showed that only tetragonal MoSi2 phase existed in the coating after being siliconized for 5 h at 900℃. The oxidation film formed on the uncoated sample was not dense, so that oxygen diffused easily through it. The volatilization of MoO3 resulted in the oxidation film separating from the substrate. The MoSi2 coating was proved to be an effective method to prevent 30 at.% Mo5Si3/MoSi2 composites from being oxidized at 1200℃. A dense glassy SiO2 film was formed on the MoSi2 coating surface, which acted as a barrier layer for the diffusion of oxygen atoms to the substrate. The 30at.% MosSi3/MoSi2 composites with a MoSi2 coating showed much better oxidation resistance at high temperature.