合金元素对TiC/奥氏体界面稳定性影响的第一性原理计算

界面结合强度与材料的强度、硬度、耐磨损、耐腐蚀等性能息息相关，TiC是钢中常见的析出相，研究它与铁基体的界面结合状态，探寻合理的界面强度提升方案，对提升钢的性能具有十分重要的理论意义和应用价值.本文以TiC/奥氏体基体界面为研究对象，采用基于密度泛函理论的第一性原理计算方法从原子尺度上研究TiC/奥氏体基体界面的结合状态.首先本文对界面结合强度以及电子结构进行了计算分析，之后进行高通量计算，研究过渡族金属元素(Mn、Tc、Re、Ru、Os、Co、Rh和Ir)在TiC/奥氏体基体界面的偏析行为及其对界面结合强度的影响，最后通过差分电荷密度分析并解释过渡族金属元素的作用机理.计算研究表明，掺杂Re元素可显著提升界面的强度，为实验上设计高性能钢铁材料提供了新的思路.

First-principles calculation of the effect of alloying elements on the stability of TiC/ austenite interface

TiC is one of the most common precipitate in steel. The interface between TiC and iron matrix has an important influence on the properties of steel. Improving the interfacial bonding strength can greatly improve the strength, hardness, wear resistance and corrosion resistance of materials. Therefore, it is of great theoretical significance and application value to explore a reasonable scheme to improve the interfacial strength. Taking the interface of TiC / austenite matrix as an example, the first principles calculation method based on density functional theory was used to investigate the interface bonding state of TiC / austenite matrix at atomic and electronic scales. Firstly, the atomic topological structure of TiC / austenite interface was optimized. On this basis, the interfacial bonding strength and electronic structure were studied. Furthermore, the segregation behavior of transition metal elements Mn, Tc, Re, Ru, OS, Co, Rh and Ir at the TiC / austenite interface and their effects on the interfacial bonding strength were systematically analyzed by high-throughput calculation, and the mechanism was explained by differential charge density analysis. The results show that the interface strength can be significantly improved by doping Re, which provides a new idea for the design of high-performance steel materials.