摘要
通过透射电镜对Fe-25％Cr-6％Al-RE(富镧)合金氧化行为进行研究.结果表明:经1200℃恒温2h纯氧中氧化,合金中镧以六方La_2O_3微小颗粒沉淀在氧化膜中α—Al_2O_3晶粒的顶端及晶界上。它们阻碍铝向表面扩散,抑制氧化膜的侧向生长;在1200℃/室温之间热循环氧化历程.稀土组元加快了合金的内氧化。它们以氧化铝、氧化镧形式出现,在靠近氧化膜/金属界面,立方La_2O_3颗粒平行于晶界并在合金基体上沉积。
The oxidation behavior of Fe-25%Cr-6%Al-RE(rich Lanthanum) alloy in pure oxygen at 1 200℃ has been examined by transmission electron microscopy. It was shown: after oxidation at 1 200℃ for 2 h Lanthanum in alloy precipitated as hexagonal structure La2O3 particles at the top of α-Al2O3 grains or the grain boundaries in the oxide scale. The aluminium atoms outward diffusion and the lateral growth of the oxide scale are prenvented; during 1 200℃ / room temperature thermal cyclic oxidation, rare, earth elements could speed up internal oxidation rate as alumina and lanthanum oxide appeared. A cubic La2O3 particles parallel to the grain boundaries in the alloy.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
1993年第4期408-413,共6页
Journal of University of Science and Technology Beijing
关键词
高温氧化
氧化镧
铁铬铝合金
TEM
La2O3 percipitation ,internal oxidation ,thermal cyclic oxidation
