Incoherent tilt grain boundaries stabilized by stacking faults and solute-cluster segregation: a case-study of an Mg-Gd alloy
Zhengqing Liu, Qi Qian, Yong Jiang, Yiren Wang, Yuman Zhu, Jian‐Feng Nie
Abstract
Despite their wide presence in hcp metals, incoherent tilt grain boundaries (ITGBs) are rarely studied. In this work, first-principles calculations were combined with atomic-resolution HAADF-STEM analyses to investigate the structure and formation of one special type ITGB in an Mg-Gd alloy featured with a unique Gd-rich cluster segregation pattern. Our results suggested this ITGB as a mirror-glide boundary formed by gliding the atoms along [202¯1¯] of a {101¯4}<202¯1¯> coherent twin boundary due to its interaction with stacking faults. The ITGB can be further stabilized by partial-column Gd substitution, leading to the observed unique segregation pattern.
Topics & Concepts
Materials scienceGrain boundaryStackingCluster (spacecraft)CrystallographyAlloyTilt (camera)Crystal twinningWork (physics)Chemical physicsMolecular physicsMicrostructureMetallurgyThermodynamicsGeometryNuclear magnetic resonancePhysicsChemistryProgramming languageComputer scienceMathematicsMagnesium Alloys: Properties and ApplicationsMicrostructure and mechanical propertiesAluminum Alloy Microstructure Properties