Oxidation process of lanthanum hexaboride ceramics
来源期刊：Rare Metals2002年第2期
论文作者：ZHENG Shuqi, MIN Guanghui, ZOU Zengda , YU Huashun, HAN Jiande , and WANG Weiti School of Materials Science and Engineering, Shandong University, Jinan , China
文章页码：101 - 105
摘 要：<正>Oxidation process of lanthanum hexaboride （LaB6） ceramic powder was investigated . The LaB6 powder sam-ples were heated continually from room temperature to 1 473 K at a heating rate of 10 K/min by differential scanning calorimetry. The oxidation tests were conducted at different exposure temperatures. The phases and morphologies of the samples before and after exposure were analyzed by XRD and SEM. It was pointed out that before 1 273 K, LaB6 has high oxidation resistant ability, which was due to that the oxide layer hinders the oxygen diffusion from outer to the sur-face of LaB6 grains. The oxide layer was composed of the transition phases, which were composed of La2O3 and B2O3 formed from the initial oxidation; when the oxidation temperature exceeded 1 273 K, protective layer was destroyed due to the vaporization of liquid B2O3. Based on the results of X-ray diffraction analysis, oxidation process of LaB6 ceramic powder can be described as follows: Before 1 273 K, lanthanum borate, La（BO2）3 was formed
ZHENG Shuqi, MIN Guanghui, ZOU Zengda , YU Huashun, HAN Jiande , and WANG Weiti School of Materials Science and Engineering, Shandong University, Jinan 250061, China
摘 要：<正>Oxidation process of lanthanum hexaboride （LaB6） ceramic powder was investigated . The LaB6 powder sam-ples were heated continually from room temperature to 1 473 K at a heating rate of 10 K/min by differential scanning calorimetry. The oxidation tests were conducted at different exposure temperatures. The phases and morphologies of the samples before and after exposure were analyzed by XRD and SEM. It was pointed out that before 1 273 K, LaB6 has high oxidation resistant ability, which was due to that the oxide layer hinders the oxygen diffusion from outer to the sur-face of LaB6 grains. The oxide layer was composed of the transition phases, which were composed of La2O3 and B2O3 formed from the initial oxidation; when the oxidation temperature exceeded 1 273 K, protective layer was destroyed due to the vaporization of liquid B2O3. Based on the results of X-ray diffraction analysis, oxidation process of LaB6 ceramic powder can be described as follows: Before 1 273 K, lanthanum borate, La（BO2）3 was formed
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