Resumo

PASCUET, M.I  e  MARTINEZ, E. Obstruction to movement in edge dislocations ½ <111> {110} by Cu, Mn and Ni solutes. An. AFA [online]. 2016, vol.27, n.3, pp.96-99. ISSN 0327-358X.

The main mechanism of embrittlement of bainitic steels by irradiation is the impediment of dislocation movement. Structural defects responsible for this obstruction are a product of irradiation. In particular, Cu, Ni and Mn precipitates are considered as major contributors to embrittlement and experimental evidence indicates that preferentially locate in the area of the dislocation line. In this paper we study the effect of this segregation around edge dislocations with Burgers vector b = 1/2 [111] and the stress required for the movement. A Monte Carlo algorithm in the semi-grand canonical ensemble is used to study the alloying elements segregation to the dislocation core. The critical resolved shear stress is studied by molecular dynamics to analyze the effect of Cu atoms in a Fe-matrix containing 1%Ni-1%Mn. The results show that the stress required to move dislocations substantially increases with the presence of segregated solutes.

Palavras-chave : Dislocation mobility; Modeling; Monte Carlo.

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