Nb-Al合金高温氧化机理  

High temperature oxidation mechanism of Nb-Al alloys

作　　者：刘贵立[1] 

机构地区：[1]沈阳工业大学建筑工程学院,沈阳110023

出　　处：《物理学报》2010年第1期499-503,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50671069);辽宁省教育厅科学研究计划(批准号:2008511;20060807;2007T165);沈阳市科技计划基金(批准号:1072026100)资助的课题~~

摘　　要：通过自编软件建立了铝氧化膜与基体铌界面的原子集团模型,用递归法计算了合金的原子埋置能、原子结合能等电子参数,从电子层面分析铌合金高温氧化机理.研究表明:铝通过晶界扩散偏聚在合金表面,并与氧结合生成致密的Al2O3氧化膜,阻挡氧向铌基体扩散.晶界和稀土元素能提高氧化膜与基体间的原子结合能,增加其界面的结合强度,加强氧化膜与基体铌间的黏附性.因此,通过在合金中添加稀土元素或细化合金晶粒均能提高铌合金的抗高温氧化性能.The atomic cluster model of the interface between aluminum oxide film and the niobium matrix has been set up with our self- programmed software. By using recursion method, the atom embedding energy, the atomic binding energy and other electronic parameters have been calculated. The high temperature oxidation mechanism of niobium alloys is analysis from the electron levels. Our study shows that, aluminum segregates on the alloy surface through the grain boundary diffusion and combines with oxygen to form dense Al2O3 oxide film which blocks oxygen to diffuse into the niobium matrix. Grain boundary and rare earth elements can increase binding energy between the oxide film and the matrix and increase the bonding strength of the interface to enhance the adhesion between the oxide film and the niobium matrix. Thus, by adding rare earth elements in the alloy or refining the alloy grains, the performance of high temperature oxidation resistance of niobium alloys can be improved.

关 键 词：电子结构 高温氧化 铌合金 

分 类 号：TG174.4[金属学及工艺—金属表面处理]