Evidence of Stress Development as a Source of Driving Force for Grain-Boundary Migration in a Ni Bicrystalline TEM Specimen

• Published in: Materials Vol. 13; no. 2; p. 360
• Main Authors: Lee, Sung Bo, Jung, Jinwook, Han, Heung Nam
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.01.2020; MDPI
• Subjects: Bicrystals; Compressive properties; Energy; Finite element method; Grain boundary migration; High resolution electron microscopy; Ion beams; Lamella; nickel; stacking fault; Stacking faults; stress development; Stress state; Transmission electron microscopy; transmission electron microscopy (tem); nickel; transmission electron microscopy (TEM); stacking fault; grain-boundary migration; stress development
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma13020360

In a previous study, using high-resolution transmission electron microscopy (HRTEM), we examined grain-boundary migration behavior in a Ni bicrystal. A specimen for transmission electron microscopy (TEM) was prepared using focused ion beam. The Ni lamella in the specimen was composed of two grains with surface normal directions of [1 0 0] and [1 1 0]. As the lamella was heated to 600 °C in a TEM, it was subjected to compressive stresses. The stress state of the Ni lamella approximated to the isostress condition, which was confirmed by a finite element method. However, the stress development was not experimentally confirmed in the previous study. In the present study, we present an observation of stacking faults with a length of 40-70 nm at the grain boundary as direct evidence of the stress development.