Effects of alloying elements X (X=Zr, V, Cr, Mn, Mo, W, Nb, Y) on ferrite/TiC heterogeneous nucleation interface: first-principles study

The segregation behavior of alloying elements X (X=Zr, V, Cr, Mn, Mo, W, Nb, Y) on the ferrite (100)/TiC(100) interface has been investigated using first principles method, and the work of separation and interface energy of ferrite/TiC interfaces alloyed by these elements were also analyzed. The results indicated that all these alloying additives except Y were thermodynamically favorable because of the negative segregation energy, showing that they have the tendency to segregate to the ferrite/TiC interface. When the Fe atom in the ferrite/TiC interface is replaced by Y, Zr, or Nb, the adhesive strength of the interface will be weakened due to the lower separation work, larger interfacial energy, and weaker electron effects. However, the introduction of Cr, Mo, W, Mn and V will improve the stability of the ferrite/TiC interface through strong interaction between these elements and C, and Cr-doped interface is the most stable structure. Therefore, the Cr, Mo, W, Mn and V in ferrite side of the interface can effectively promote ferrite heterogeneous nucleation on TiC surface to form fine ferrite grain.