It is well known that impurities in iron which segregate to grain boundaries can dramatically change physical properties. Carbon and boron tend to increase ductility while phosphorous and sulphur lead to embrittlement. Cohesion at boundaries in iron can be understood by studying changes in the iron d states responsible for bonding. Since the effects are quite localized, relatively small systems can be used to model the electronic structure. Both FLAPW and LKKR calculations show that the average energy of the d band is lower for B and C impurities and higher for P and S impurities. These results are consistent with the macroscopic changes in cohesion.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Metals and Alloys