Počet záznamů: 1

The effect of segregated sp-impurities on grain-boundary and surface structure, magnetism and embrittlement in nickel

  1. 1.
    0366251 - UFM-A 2012 RIV GB eng J - Článek v odborném periodiku
    Všianská, Monika - Šob, Mojmír
    The effect of segregated sp-impurities on grain-boundary and surface structure, magnetism and embrittlement in nickel.
    Progress in Materials Science. Roč. 56, č. 6 (2011), s. 817-840 ISSN 0079-6425
    Grant CEP: GA AV ČR IAA100100920; GA MŠk(CZ) OC10008; GA ČR GD106/09/H035
    Výzkumný záměr: CEZ:AV0Z20410507
    Klíčová slova: grain boundaries * segregation * nickel * embrittlement
    Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
    Impakt faktor: 18.216, rok: 2011

    We present a theoretical study of segregation of sp-elements (Al, Si, P, S,Ga, Ge, As, Se, In, Sn, Sb and Te) at the Sigma5(210) grain boundary (GB) and (210) free surface (FS) in fcc ferromagnetic Ni. Whereas there is a slight enhancement of magnetization at the clean GB and FS with respect to bulk nickel (3–7% and 24%, respectively), the studied impurities entirely kill or strongly reduce ferromagnetism at the GB/FS and in its vicinity so that magnetically dead layers are formed. This effect is due to the hybridization of the impurity sp-states and Ni d-states. We determine the preferred segregation sites at the Sigma5(210) GB for the sp-impurities, their segregation enthalpies and strengthening/embrittling energies with their chemical and mechanical components. We find interstitially segregated Si and P and substitutionally segregated Al as a GB cohesion enhancer and interstitially segregated S, Ge, As, Se and substitutionally segregated Ga, In, Sn, Sb and Te as GB embrittlers in Ni.
    Trvalý link: http://hdl.handle.net/11104/0201304