中国物理B ›› 2014, Vol. 23 ›› Issue (3): 37102-037102.doi: 10.1088/1674-1056/23/3/037102
• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇 下一篇
李春霞a b c, 党随虎a b c, 王丽萍a b, 张彩丽a b, 韩培德a b
Li Chun-Xia (李春霞)a b c, Dang Sui-Hu (党随虎)a b c, Wang Li-Ping (王丽萍)a b, Zhang Cai-Li (张彩丽)a b, Han Pei-De (韩培德)a b
摘要: Effects of Cr, Mo, and Nb on the ferritic stainless steel ∑(210) grain boundary and intragranularity are investigated using the first-principles principle. Different positions of solute atoms are considered. Structural stability is lowered by Cr doping and enhanced by Mo and Nb doping. A ranking on the effect of solute atoms enhancing the cohesive strength of the grain boundary, from the strongest to the weakest is Cr, Mo, and Nb. Cr clearly prefers to locate in the intragranular region of Fe rather than in the grain boundary, while Mo and Nb tend to segregate to the grain boundary. Solute Mo and Nb atoms possess a strong driving force for segregation to the grain boundary from the intragranular region, which increases the grain boundary embrittlement. For Mo-and Nb-doped systems, a remarkable quantity of electrons accumulate in the region close to Mo (Nb). Therefore, the bond strength may increase. With Cr, Mo, and Nb additions, an anti-parallel island is formed around the center of the grain boundary.
中图分类号: (Density functional theory, local density approximation, gradient and other corrections)