loading page

Modelling of Cavity Nucleation, Early-stage Growth and Sintering in Polycrystal under Creep-fatigue Interaction
  • +1
  • J.-D. Hu,
  • C.-J. Liu,
  • Fuzhen Xuan,
  • Bo Chen
J.-D. Hu
East China University of Science and Technology School of Mechanical Engineering and Power Engineering
Author Profile
C.-J. Liu
East China University of Science and Technology School of Mechanical Engineering and Power Engineering
Author Profile
Fuzhen Xuan
East China University of Science and Technology School of Mechanical Engineering and Power Engineering
Author Profile
Bo Chen
University of Leicester
Author Profile

Abstract

A mechanistic based cavitation model that considers nucleation, early-stage growth and sintering under creep-fatigue interaction is proposed. The number density of cavities ρ and their evolution during multi-cycle creep-fatigue loading are predicted. Both the cavity nucleation and early-stage growth rates, controlled by grain boundary (GB) sliding mechanism during the tension phase, are formulised as a function of local normal stress σ n. The cavity sintering that occurs during the compression phase is described as a function of σ n, but the mechanism switches to the unconstrained GB diffusion. By examining various load waveform parameters, results provide important insights into experimental design of studying the creep-dominated cavitation process under creep-fatigue interaction. First, creep-fatigue test with initial compression will promote higher ρ value compared to that with initial tension, if the unbalanced stress hold time in favour of tension is satisfied. Second, the ρ value does not have a monotonic dependence on either the compressive hold time or stress level, because of their competing effect on nucleation and sintering. Third, the optimum value of stress variation rate exists in terms of obtaining the highest ρ value due to sintering effect.

Peer review status:UNDER REVIEW

09 Jun 2021Submitted to Fatigue & Fracture of Engineering Materials & Structures
09 Jun 2021Submission Checks Completed
09 Jun 2021Assigned to Editor
13 Jun 2021Reviewer(s) Assigned
23 Aug 2021Review(s) Completed, Editorial Evaluation Pending
25 Aug 2021Editorial Decision: Revise Major
06 Sep 20211st Revision Received
06 Sep 2021Submission Checks Completed
06 Sep 2021Assigned to Editor
06 Sep 2021Reviewer(s) Assigned