The segregation effects of Nb and V on bcc FeSigma3[110](111) grain boundary cohesion are studied by the first-principles DMol method within the framework of density functional theory. The calculated segregation energy difference between the grain boundary and the corresponding free surface is -0.51 eV (-0.58 eV) for solute Nb (V), which indicates that both Nb and V could enhance the grain boundary cohesion in body-centred-cubic Fe. We found that the chemical effect and the geometry effect of Nb (V) play crucial but opposite roles in determining whether a material is brittle or ductile. The chemical effect is dominant and advantageous for grain boundary cohesion. Also, Nb and V show very different behaviours: in chemical effect, Nb is more conducive to ductility than V; while in the geometry effect, Nb is less conducive to ductility and more conducive to embrittlement than V.
部门归属
cent iron & steel res inst, beijing 100081, peoples r china. tsing hua univ, dept phys, beijing 100084, peoples r china. acad sinica, int ctr mat phys, shenyang 110016, peoples r china.;shang, jx (reprint author), cent iron & steel res inst, beijing 100081, peoples r china
J. X. Shang,C. Y. Wang. Electronic effects of alloying elements Nb and V on body-centred-cubic Fe grain boundary cohesion[J]. Journal of Physics-Condensed Matter,2001,13(42):9635-9644.
APA
J. X. Shang,&C. Y. Wang.(2001).Electronic effects of alloying elements Nb and V on body-centred-cubic Fe grain boundary cohesion.Journal of Physics-Condensed Matter,13(42),9635-9644.
MLA
J. X. Shang,et al."Electronic effects of alloying elements Nb and V on body-centred-cubic Fe grain boundary cohesion".Journal of Physics-Condensed Matter 13.42(2001):9635-9644.
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