This article presents a comprehensive study of the oxidation behavior of silicon molybdenum rod (SiMo) at high temperatures. The study aims to investigate the oxidation process, analyze the mechanism behind the oxidation behavior, and provide insights into the development of protective coatings for SiMo.
Introduction: Silicon molybdenum (SiMo) is a refractory material with high melting point and excellent resistance to high temperatures and oxidation. It is widely used in aerospace, atomic energy, and other high-tech fields due to its unique physical and chemical properties. However, the oxidation of SiMo under high-temperature conditions can significantly affect its mechanical and physical properties, leading to serious safety issues. Therefore, studying the oxidation behavior of SiMo is of great significance for improving its service performance and extending its application scope.
Experimental methods: In this study, pure SiMo rods were used as samples. The samples were cut into uniform lengths and polished. The oxidation behavior of the samples was studied in a high-temperature furnace at temperatures ranging from 600°C to 1000°C. The furnace was continuously purged with pure argon to maintain an inert atmosphere. The weight gain of the samples was recorded using a sensitive balance system connected to a computer, and the surface morphology of the samples was observed using scanning electron microscopy (SEM).
Experimental results: The weight gain of the SiMo samples increased gradually with increasing temperature. At 600°C, the weight gain was relatively low, but it increased rapidly above 800°C. SEM images showed that the surface of the SiMo samples became rougher with increasing temperature, and small pores and cracks were observed at high temperatures.
Experimental analysis: The oxidation of SiMo at high temperatures is a complex process involving many factors, including temperature, humidity, oxygen concentration, and surface morphology. In this study, the oxidation behavior of SiMo was primarily affected by temperature and oxygen concentration. At low temperatures, the oxidation rate was relatively slow, but it accelerated rapidly above 800°C due to the activation of surface atoms and the easier diffusion of oxygen atoms through the surface oxide layer. In addition, the surface morphology of SiMo also played a crucial role in its oxidation behavior. Rougher surfaces with more defects and irregularities can provide more nucleation sites for oxide growth, leading to a faster oxidation rate.
Conclusion: This study has shown that the oxidation behavior of SiMo is strongly dependent on temperature and surface morphology. At low temperatures, the oxidation rate is relatively slow, but it increases rapidly above 800°C due to surface activation and easier oxygen diffusion through the oxide layer. Surface roughness and defects can also accelerate the oxidation rate by providing more nucleation sites for oxide growth. These findings provide valuable information for understanding the oxidation behavior of SiMo and developing protective coatings to improve its service performance.