【摘要】 对Si-Al-Y-O-N系统气压烧结的致密氮化硅陶瓷的氧化研究表明,材料在1100～1400℃温度下氧化,符合抛物线氧化规律。在此温度范围内,氧化活化能为600～730kJ/mol。AlN的引入对材料在低温段(800～1000℃)的抗氧化能力有较大影响。由于在晶界存在易氧化的第二相物质,含AlN作添加剂的氮化硅材料在低温段有较明显的氧化,氧化呈线性规律。更多还原

【Abstract】 Oxidation behavior of gas pressure-sintered silicon nitride ceramics with Y₂O₃, Al₂O₃ and AIN additives in the temperature range of 800～1400℃ has been studied. Oxidation of the material tested between 1100～1400℃ follows the typical parabolic law of kinetics with an activation energy of 600～730kJ/mol. The diffusion of ions of additives and impurities segregated at the grain boundaries toward the surface of specimere is a rate-controlling step. The incorporation of AIN decreases the oxidation resistance of silicon nitride in the temperature range of 800～1000℃ due to the formation of the second phase material at the grain boundaries. The oxidation of silicon nitride ceramics with AIN additive correlates with time linearly at 800～1000℃.更多还原