耐火与石灰 ›› 2023, Vol. 48 ›› Issue (5): 29-33.

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氧化镁晶须在镁质材料表界面的生长机制

  

  1. ( 江苏嘉耐高温材料股份有限公司,宜兴 214200)
  • 出版日期:2023-10-10 发布日期:2023-11-01

Growth mechanism of magnesium oxide whiskers on the surface and interface of magnesium-based materials

  1. (Jiangsu Chianaref Refractory Co.,Ltd.,Yixing 214200,China) 
  • Online:2023-10-10 Published:2023-11-01

摘要: 采用烧结镁砂、电熔镁砂、硅微粉为原料制备了镁质浇注料,发现在镁质浇注料中引入碳化硅粉可在浇注 料表界面形成纤维针状 MgO 晶须。对比分析了碳化硅细粉添加量和热处理温度对氧化镁晶须的影响,在低氧分压区 域在达到 1 450 ℃以上时镁热还原反应导致镁蒸气迁移至材料表界面,氧化后析出 MgO 晶须。添加量为 3% ~ 7% 的 97% 碳化硅细粉的镁硅质试样表面在 1 500 ℃热处理 3 h 容易集聚氧化镁晶须,且随着碳化硅添加量的增加,晶须生 成量及发育情况均得到改善。

关键词: 镁质材料, 碳化硅, 氧化镁晶须, 生长机制

Abstract: For the magnesia based castable made up with sintered magnesia,fused magnesia,and silica powder,it was found that the addition of silicon carbide powder can create fibrous needle MgO whiskers on the surface and interface of the castable. The impact of the dosage of silicon carbide fine powder and heat treatment temperature on magnesium oxide whiskers are compared and analyzed. When the temperature reached above 1 450 ℃ in the low oxygen partial pressure region, the magnesium thermal reduction reaction will cause the migration of magnesium vapor to the material surface and interface,and MgO whiskers grow after oxidation. The surface of magnesium siliceous samples with addition of 3% to 7% of 97% silicon carbide fine powder is prone to agglomeration of magnesium oxide whiskers after 3 hours of heat treatment at 1 500 ℃ . Moreover, as the dosage of silicon carbide increases,the generation and growth of whiskers are improved.

Key words: Magnesium material, Silicon carbide, Magnesium oxide whiskers, Growth mechanism

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