Cell boundary engineering of ferrous medium-entropy alloy fabricated by laser powder bed fusion

Park, Jeong Min; Kwon, Hyeonseok; Choe, Jungho; Kim, Kyung Tae; Yu, Ji-Hun; Heo, Yoon-Uk; Kim, Hyoung Seop

doi:10.1016/j.scriptamat.2023.115715

Cited by 12 publications

(1 citation statement)

References 40 publications

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“…To fully understand the cellular structure behaviors, there remains a question of how to quantitatively measure the misorientations between the sub-micro cellular structures. Unlike the traditional large-angle grain boundary, the misorientation across the cellular boundaries in LPBF 316L SS is usually very low, and the number of fractions is unavailable to be measured directly, especially when the ultra-low misorientation is smaller than 2 • using conventional electron backscatter diffraction (EBSD); however, line profiles of the misorientation angle and kernel average misorientation (KAM) map measured by EBSD analysis can indicate a misorientation smaller than 2 • [10,17,26,27]. Traditional techniques like EBSD associated with scanning electron microscopy (SEM) require a large interaction volume between the electrons from the beam and the atoms of the materials, thereby lacking spatial resolution and causing inaccurate correspondence between the misorientation and dislocation cell.…”

Section: Introductionmentioning

confidence: 99%

Delineating the Ultra-Low Misorientation between the Dislocation Cellular Structures in Additively Manufactured 316L Stainless Steel

Sun,

Adachi,

Sato

et al. 2024

Materials

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Sub-micro dislocation cellular structures formed during rapid solidification break the strength–ductility trade-off in laser powder bed fusion (LPBF)-processed 316L stainless steel through high-density dislocations and segregated elements or precipitates at the cellular boundaries. The high-density dislocation entangled at the cellular boundary accommodates solidification strains among the cellular structures and cooling stresses through elastoplastic deformation. Columnar grains with cellular structures typically form along the direction of thermal flux. However, the ultra-low misorientations between the adjacent cellular structures and their interactions with the cellular boundary formation remain unclear. In this study, we revealed the ultra-low misorientations between the cellular structures in LPBF-processed 316L stainless steel using conventional electron backscatter diffraction (EBSD), transmission Kikuchi diffraction (TKD), and transmission electron microscopy (TEM). The conventional EBSD and TKD analysis results could provide misorientation angles smaller than 2°, while the resolution mainly depends on the specimen quality and scanning step size, and so on. A TEM technique with higher spatial resolution provides accurate information between adjacent dislocation cells with misorientation angles smaller than 1°. This study presents evidence that the TEM method is the better and more precise analytical method for the misorientation measurement of the cellular structures and provides insights into measuring the small misorientation angles between adjacent dislocation cells and nanograins in nanostructured metals and alloys with ultrafine-grained microstructures.

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Section: Introductionmentioning

confidence: 99%