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为了从电子层面揭示Nb合金高温氧化的物理本质,采用递归法计算了Nb合金的电子态密度、原子镶嵌能、亲和能等电子结构参数,探索Nb合金高温氧化机理.研究表明:氧在Nb中具备较高的扩散速率和溶解度,且氧与Nb较易发生反应,生成氧化物,这使Nb的抗高温氧化性较差.原子镶嵌能的计算结果表明,合金元素Ti,Si,Cr在基体中稳定性较低,易向Nb合金表面扩散,形成富Ti,Si,Cr的表层.合金表层中氧与Nb,Ti,Si,Cr间具有较大亲和性,可以生成相应的氧化物,形成对合金具有保护作用的氧化膜.
In order to reveal the physical nature of high temperature oxidation of Nb alloy from the electron level, the electronic structure parameters such as electronic density of states, atomic inlay energy, affinity energy and other electronic structure parameters of Nb alloy were calculated by recursive method, and the mechanism of high temperature oxidation of Nb alloy was explored. Has higher diffusion rate and solubility, and oxygen and Nb are more likely to react, generating oxides, which makes the high temperature oxidation resistance of Nb is poor.Atomic mosaic energy calculation results show that alloying elements Ti, Si, Cr in The stability of the matrix is low, easy to spread to the Nb alloy surface, the formation of rich Ti, Si, Cr surface layer of alloy oxygen and Nb, Ti, Si, Cr between the larger affinity can generate the corresponding oxides , Forming an oxide film with a protective effect on the alloy.