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Influence of hydrogen environment on dislocation nucleation and fractureresponse of〈110〉grain boundaries in nickel

Journal Article


Abstract


  • The segregation of solute H has a profound effect on mechanical properties of grain boundaries (GBs). In this work, systematic molecular dynamics (MD) simulations have been performed to elucidate the influence of H environment on dislocation nucleation process and fracture response of different Ni GBs. The results show that the effect of H on dislocation nucleation depends strongly on GB structures. The presence of H decreases the yield stress required to nucleate dislocations from GBs with C and D structural units (SUs), while increases the yield stress of GBs with E SUs. This difference is attributed to different deformation mechanisms related to the dislocation nucleation from various GBs with H. By analysing the decohesion results, it is found that H has stronger embrittling effect on GBs with E SUs than C and D SUs, originating from the fact that H significantly elongates the Ni-Ni bonds around the open E SUs while slightly expands the compact C and D SUs. These findings present fundamental understanding on H embrittlement mechanism and provide mechanistic insights for engineering microstructure against H embrittlement in metallic materials.

Authors


  •   Li, Jiaqing (external author)
  •   Lu, Cheng
  •   Pei, Linqing (external author)
  •   Zhang, Che (external author)
  •   Wang, Rui (external author)
  •   Tieu, A Kiet.

Publication Date


  • 2019

Citation


  • Li, J., Lu, C., Pei, L., Zhang, C., Wang, R. & Tieu, K. (2019). Influence of hydrogen environment on dislocation nucleation and fractureresponse of〈110〉grain boundaries in nickel. Computational Materials Science, 165 40-50.

Scopus Eid


  • 2-s2.0-85064484867

Number Of Pages


  • 10

Start Page


  • 40

End Page


  • 50

Volume


  • 165

Place Of Publication


  • Netherlands

Abstract


  • The segregation of solute H has a profound effect on mechanical properties of grain boundaries (GBs). In this work, systematic molecular dynamics (MD) simulations have been performed to elucidate the influence of H environment on dislocation nucleation process and fracture response of different Ni GBs. The results show that the effect of H on dislocation nucleation depends strongly on GB structures. The presence of H decreases the yield stress required to nucleate dislocations from GBs with C and D structural units (SUs), while increases the yield stress of GBs with E SUs. This difference is attributed to different deformation mechanisms related to the dislocation nucleation from various GBs with H. By analysing the decohesion results, it is found that H has stronger embrittling effect on GBs with E SUs than C and D SUs, originating from the fact that H significantly elongates the Ni-Ni bonds around the open E SUs while slightly expands the compact C and D SUs. These findings present fundamental understanding on H embrittlement mechanism and provide mechanistic insights for engineering microstructure against H embrittlement in metallic materials.

Authors


  •   Li, Jiaqing (external author)
  •   Lu, Cheng
  •   Pei, Linqing (external author)
  •   Zhang, Che (external author)
  •   Wang, Rui (external author)
  •   Tieu, A Kiet.

Publication Date


  • 2019

Citation


  • Li, J., Lu, C., Pei, L., Zhang, C., Wang, R. & Tieu, K. (2019). Influence of hydrogen environment on dislocation nucleation and fractureresponse of〈110〉grain boundaries in nickel. Computational Materials Science, 165 40-50.

Scopus Eid


  • 2-s2.0-85064484867

Number Of Pages


  • 10

Start Page


  • 40

End Page


  • 50

Volume


  • 165

Place Of Publication


  • Netherlands