摘要
以板状刚玉颗粒和细粉、Al_(2)O_(3)微粉、Si粉和Al粉为原料,以酚醛树脂为结合剂,在流通氮气中于1450℃保温72 h制备了β-SiAlON结合刚玉复合材料试样。研究了不同温度(900~1300℃)下热震以及热震循环次数对试样氧化行为的影响。结果表明:与无热震条件下相比,热震作用下试样在不同温度下氧化后的质量增加率明显增加。随热震循环次数的增加,氧化后试样的质量增加率增加,表明热震使得材料的氧化加剧。热震作用下试样氧化加剧的原因在于:无热震时β-SiAlON氧化后在试样表面形成致密氧化保护膜,可阻止氧气进入内部;而热震可使试样表面的氧化保护膜破裂,产生较多微裂纹,为氧气进入试样内部提供通道,进而加速材料氧化。
β-SiAlON bonded corundum composite was prepared using tabular corundum particles and fines,Al_(2)O_(3)micropowder,Si and Al powders as starting materials,phenolic resin as the binder,firing at 1450℃for 72 h in flowing N 2.Effects of thermal shock and thermal shock cycles on oxidation behavior of the composite at different temperatures(900-1300℃)were investigated.The results show that:the mass gain rate of the specimens oxidized at different temperatures with thermal shock is higher than without thermal shock,and the rate increases with the thermal shock cycle increasing,indicating that thermal shock can promote the oxidation.The reason of serious oxidation under thermal shock condition is as follows:without thermal shock,a dense oxidation protective layer is formed on the surface of the specimen afterβ-SiAlON oxidation,preventing oxygen diffusion into the inner.However,the oxidation protective layer is broken under thermal shock condition producing more microcracks,which provides passages for oxygen to enter the inner part of the specimen,thus accelerating the oxidation.
作者
田学坤
文钰斌
凌永一
王珍
杨金松
刘新红
Tian Xuekun;Wen Yubin;Ling Yongyi;Wang Zhen;Yang Jinsong;Liu Xinhong(Henan Key Laboratory of High Temperature Functional Ceramics,School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450052,Henan,China)
出处
《耐火材料》
CAS
北大核心
2021年第5期417-422,共6页
Refractories
基金
国家自然科学基金资助项目(51872266,51672253)。
