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TiB2-HfC陶瓷的高温抗氧化性能

Oxidation resistance of TiB2-HfC ceramic at high temperature

  • 摘要: 为了研究TiB2-HfC陶瓷的高温抗氧化性能, 分析了TiB2-HfC陶瓷在1100 ℃下分别氧化1、4、7、10 h后的氧化行为; 根据材料氧化后的微观结构, 对陶瓷氧化层进行了划分, 将其分为外氧化层、次氧化层及过渡层。实验结果表明: 外氧化层的氧化物为TiO2、B2O3、HfO2、NiO和CoO; 随着氧化时间的延长, 材料发生了严重氧化, 氧化层逐渐变厚, 材料保有的抗弯强度逐渐减小, 材料的氧化增重与氧化时间呈抛物线规律; 氧化1h后, 材料表面形成了约为12 μm的致密氧化层, 此时材料具有较好的抗氧化性能, 且仍保有较高的抗弯强度, 其值为823.6 MPa。

     

    Abstract: Oxidation behavior of the TiB2-HfC ceramic oxidized at 1100 ℃ for 1, 4, 7, 10 h was investigated to analyze the oxidation resistance of TiB2-HfC ceramic at high temperature. According to the microstructure of TiB2-HfC ceramic after oxidation, the oxidation layers were divided into the outer oxide layer, the sub-oxidation layer, and the transition layer. The results show that the TiO2, B2O3, HfO2, NiO, and CoO exist in the outer oxidation layer. With the increase of the oxidation time, the TiB2-HfC ceramic is seriously oxidized, the oxide layer becomes thicker, and the bending strength decreases gradually. The oxidation gain and oxidation time were parabolic. After the oxidation for 1 h, a dense oxide layer with the thickness of about 12 μm is formed on the surface of the TiB2-HfC ceramic. At this time, the TiB2-HfC ceramic shows a better oxidation resistance and still has a relatively high bending strength, which is 823.6 MPa.

     

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