First-principles theory calculations were used to investigate the segregation behavior of P and Mg as well as the interactions between Mg and P atα-FeΣ3(111)[11¯0]symmetrical tilt grain boundary(GB).Results dem...First-principles theory calculations were used to investigate the segregation behavior of P and Mg as well as the interactions between Mg and P atα-FeΣ3(111)[11¯0]symmetrical tilt grain boundary(GB).Results demonstrate that both P and Mg are segregated at GB,and P has a stronger segregation potency.Mg prefers to substitute at grain boundary plane with the largest absorbable vacancy,whereas P inclines to substitute at the sites near Fe atoms to form strong covalent Fe-P bonds.When Mg exists at GB,the segregation behavior of P may be greatly inhibited by the decrease in possible solution sites and the increase in segregation energy.P has stronger interactions with Mg at GB,forming a lower energy hybridization peak.These results can be used to explain why the addition of a small amount of Mg can ameliorate the temper embrittlement phenomenon.展开更多
文摘First-principles theory calculations were used to investigate the segregation behavior of P and Mg as well as the interactions between Mg and P atα-FeΣ3(111)[11¯0]symmetrical tilt grain boundary(GB).Results demonstrate that both P and Mg are segregated at GB,and P has a stronger segregation potency.Mg prefers to substitute at grain boundary plane with the largest absorbable vacancy,whereas P inclines to substitute at the sites near Fe atoms to form strong covalent Fe-P bonds.When Mg exists at GB,the segregation behavior of P may be greatly inhibited by the decrease in possible solution sites and the increase in segregation energy.P has stronger interactions with Mg at GB,forming a lower energy hybridization peak.These results can be used to explain why the addition of a small amount of Mg can ameliorate the temper embrittlement phenomenon.
