Ti、Cr对钒抗氧化性能影响的第一性原理研究

A first principles study of the effects of Ti,Cr doping on the vanadium oxidation resistance

高温氧化是限制钒合金应用的主要原因之一.利用第一性原理计算了Ti、Cr杂质原子掺入钒基体后,O在钒合金中的杂质形成能的变化.结果表明:O杂质原子在钒中占据八面体间隙位更稳定,且杂质形成能为-4.65eV,Ti掺杂会降低O的杂质形成能,使O在晶体内部扩散更容易,Cr掺杂的情况与Ti掺杂相反.并且还计算了体系电子结构、布居分布和电荷密度,进一步分析所得到的结论与杂质形成能的计算结果一致.

High temperature oxidation is one of the main issues for restricting the applications of vanadium alloys. The variations of impurity formation energy after Ti, Cr doping are calculated by first principles. The results show that the system is more stable when O occupies the octahedral site of V, and its impurity formation energy is -4.65eV. Ti doping will decrease the impurity formation energy, so the diffusion of O in crystal is easier. While compared to Ti doping, Cr doping induces the contrary effect. Further more, the electronic structure, population distribution and charge density of system are calculated. The results by further analysis are consistent with those results of impurity formation energy.