Impact Factor:7.3
DOI number:10.1016/j.ijmecsci.2021.106494
Affiliation of Author(s):中南大学粉末冶金研究院
Teaching and Research Group:高温结构材料研究所
Journal:International Journal of Mechanical Sciences
Funded by:中国国家重点研究与发展计划（2016YFB0700300）和中国国家自然科学基金（51871092、12072109和52020105013）
Key Words:Single-crystal superalloy,Heat-treatment, Microstrutual evolution, Mechanical-behavior, Alloy simulation
Abstract:Severe residual stresses generated by various preparative techniques can greatly affect the mechanical properties in the Ni-based superalloy parts. Limited data is currently available for deeply understanding the origin of residual stress at nanoscale and in particular, for establishing the relationship between the residual stress and mechanical property to accelerate the development of the Ni-based superalloys. Here, the effect of the heat treatment on the grain growth, residual stress and flow stress in Ni-based superalloy is investigated by using an atomic simulation combined with a physically-based theoretical model. The dissociation of grain boundary causes the coalescence of adjacent grains during annealing, which is observed by atomic simulation. However, this process is different from the previous work that the curvature-driven grain-boundary migration leads to the grain growth. The residual stress consists of the grain and grain boundary, where the average value from grain boundary is about 50% higher that from the grain based on the statistical result. The grain growth and local movement of grain boundary cause the stress relaxation, and in turn they reduce the residual stress. The evolution of the residual stress is in good agreement with the previous experiment. Further, an analytical theoretical model is proposed to qualitatively evaluate the variation trend of the residual stress with the annealing temperature. It is also proved that the residual stress decreases with the increase of the annealing temperature. The present work can be applied to determine the residual stress in the annealed structure, which greatly reduces the process flow, therefore provides a scientific basis to turn the technological process for the accelerated development of the new Ni-based alloys.
Co-author:Li Li, Qihong Fang, Jia Li, Bin Liu, Zaiwang Huang
First Author:Baobin Xie
Indexed by:Article
Correspondence Author:Liming Tan
Document Code:106494
Discipline:Engineering
First-Level Discipline:冶金
Page Number:202–203
ISSN No.:0020-7403
Translation or Not:no