Tensile deformation behavior and generalized stacking fault energy surface ofγ-Fe23C6 by atomistic modelling

To investigate the fatigue behavior of steel or Ni-based superalloy, it is necessary to identify the mechanism of crack initiation and non-uniform deformation by studying the mechanical properties of M23C6 carbides. The effects of temperature, vacancies, and void on the mechanical properties of M23C6 (M = Fe) carbides are investigated by the molecular dynamics method. Furthermore, in order to identify the slip system which is the most conductive to dislocation activity for M23C6 type carbides, based on the generalized stacking fault energy (GSFE) model of Fe23C6, the three-dimensional GSFE surface is calculated. The results show that Fe23C6 is more prone to cleavage fracture along the [110] direction than along the [100] and the [111] directions at the same temperature; the void size has a great effect on the tensile stress curve of Fe23C6 along the [100] direction but has little effect on the tensile stress curve along [110] and [111] directions. The slip of Fe23C6 on the (111) plane tends to follow the [11 2] direction, and Fe23C6 is more likely to produce the dislocation structure on the (111) plane than on the (110) plane.

Automated summary

To investigate the fatigue behavior of steel or Ni-based superalloy, this study investigates the effects of temperature, vacancies, and void on the mechanical properties of M23C6 carbides using the molecular dynamics method. Additionally, the slip system that is most conducive to dislocation activity for M23C6 type carbides is identified based on the generalized stacking fault energy (GSFE) model. The results indicate that cleavage fracture is more likely to occur along the [110] direction for Fe23C6 and that void size affects the tensile stress curve along the [100] direction but has little effect on the stress curve along [110] and [111] directions.