Affiliation:
1. Shi-Changxu Innovation Center for Advanced Materials Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 P. R. China
2. School of Materials Science and Engineering University of Science and Technology of China Shenyang 110016 P. R. China
3. School of Materials Science and Engineering Chongqing Jiaotong University Chongqing 400074 P. R. China
4. SuZhou Laboratory Suzhou 215028 P. R. China
Abstract
The atomistic simulations in this article substantiate that grain boundary stress fields remain unaffected by changes in their area, aligning with the Olson–Cohen theory which supports that such area insensitivity is an inherent outcome of the combined effect of coherency and anti‐coherency dislocations. Twist grain boundaries are employed in α‐iron as a model in atomistic simulations, revealing and contrasting the dislocations and stresses of these grain boundaries when their area varies from infinity to a few square nanometers. It is discovered that the grain boundary stresses remain relatively constant, always short‐ranged. Furthermore, within the framework of the Frank–Bilby equation, the line directions and spacing of coherency and anti‐coherency dislocation arrays in a grain boundary are predicted, the stresses of these dislocations are subsequently calculated numerically, and these stresses are superimposed together to form the grain boundary stress field. The numerical calculations verify that stress fields of grain boundaries are not sensitive to changes of their area, corroborating our atomistic simulations. The preliminary atomistic simulations of various homophase and heterophase boundaries further affirm this area insensitivity.
Funder
National Natural Science Foundation of China