Low-temperature oxidation behavior of MoSi_2 powders  

作　　者：Peizhong Feng Xuanhui Qu Islam S. Humail Xueli Du 

机构地区：[1]State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China [2]School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116, China

出　　处：《Journal of University of Science and Technology Beijing》2007年第6期558-561,共4页北京科技大学学报（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China (No.50025412)

摘　　要：The oxidation behavior of molybdenum disilicide （MoSi2） powders at 400, 500, and 600℃ for 12 h in air were investigated by using X-ray diffraction （XRD） and transmission electron microscopic （TEM） techniques. Significant changes were observed in volume, mass, and color. Especially at 500℃, the volume expansion was found to be as high as 7-8 times, the color changed from black to yellow-white, and the mass gain was about 169.34% after 8 h, with SiO2 and MoO3 as main reaction products. The gains in volume and mass were less at 400 and 600℃ compared with those at 500℃, probably due to the less reaction rate at 400℃ and the formation of silica glass scale at 600℃, which would protect the matrix and restrain the diffusion of oxygen and molybdenum. Thus, the accelerated oxidation behavior of MoSi2 powder appeared at 500℃ and the volume expansion was the sign of accelerated oxidation.The oxidation behavior of molybdenum disilicide （MoSi2） powders at 400, 500, and 600℃ for 12 h in air were investigated by using X-ray diffraction （XRD） and transmission electron microscopic （TEM） techniques. Significant changes were observed in volume, mass, and color. Especially at 500℃, the volume expansion was found to be as high as 7-8 times, the color changed from black to yellow-white, and the mass gain was about 169.34% after 8 h, with SiO2 and MoO3 as main reaction products. The gains in volume and mass were less at 400 and 600℃ compared with those at 500℃, probably due to the less reaction rate at 400℃ and the formation of silica glass scale at 600℃, which would protect the matrix and restrain the diffusion of oxygen and molybdenum. Thus, the accelerated oxidation behavior of MoSi2 powder appeared at 500℃ and the volume expansion was the sign of accelerated oxidation.

关 键 词：molybdenum disilicide low-temperature oxidation accelerated oxidation volume expansion 

分 类 号：O643[理学—物理化学]