Grain geometry dominated mechanical anisotropy in laser powder bed fused IN718 alloy: Insights from in-situ EBSD and DIC

Ziyi Ding; Taiqing Deng; Xuewen Li; Kesong Miao; Xiaojun Wang; Guohua Fan

doi:10.1016/j.msea.2026.150943

Grain geometry dominated mechanical anisotropy in laser powder bed fused IN718 alloy: Insights from in-situ EBSD and DIC

Ziyi Ding
, Taiqing Deng
, Xuewen Li
, Kesong Miao
, Xiaojun Wang^*
, Guohua Fan^*

^*Corresponding author for this work

Harbin Institute of Technology
China Aerospace Science and Technology Corporation
Nanjing Tech University

Research output: Contribution to journal › Article › peer-review

Abstract

This study reveals grain geometry-dominated mechanical anisotropy in laser powder bed fusion (LPBF) IN718 via in-situ EBSD and DIC. Despite a nearly random crystallographic orientation, the alloy exhibits significant strength and ductility anisotropy: transverse direction (TD) yield strength exceeds build direction (BD) yield strength by 136 MPa, whereas the uniform elongation is 28.2% lower. Through quantitative analysis of lattice rotation behaviors in grains of varying orientations, sizes, and aspect ratios during early deformation, we introduce an anisotropy coefficient (K_a) quantifying grain size and aspect ratio effects on lattice rotation. Modified strengthening models incorporating K_a demonstrate that strength anisotropy primarily arises from geometry-modulated dislocation, intrinsic, and precipitation strengthening. Ductility anisotropy originates from columnar grain-loading direction coupling: TD tension induces intergranular fracture via premature strain localization at grain boundaries, while BD tension promotes homogeneous deformation and transgranular fracture.

Original language	English
Article number	150943
Journal	Materials Science and Engineering: A
Volume	975
DOIs	https://doi.org/10.1016/j.msea.2026.150943
State	Published - Nov 2026
Externally published	Yes

Keywords

In-situ EBSD
IN718
Laser powder bed fusion
Mechanical anisotropy

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10.1016/j.msea.2026.150943

Cite this

@article{95661b41736d4675b10cd26e6e867805,

title = "Grain geometry dominated mechanical anisotropy in laser powder bed fused IN718 alloy: Insights from in-situ EBSD and DIC",

abstract = "This study reveals grain geometry-dominated mechanical anisotropy in laser powder bed fusion (LPBF) IN718 via in-situ EBSD and DIC. Despite a nearly random crystallographic orientation, the alloy exhibits significant strength and ductility anisotropy: transverse direction (TD) yield strength exceeds build direction (BD) yield strength by 136 MPa, whereas the uniform elongation is 28.2\% lower. Through quantitative analysis of lattice rotation behaviors in grains of varying orientations, sizes, and aspect ratios during early deformation, we introduce an anisotropy coefficient (Ka) quantifying grain size and aspect ratio effects on lattice rotation. Modified strengthening models incorporating Ka demonstrate that strength anisotropy primarily arises from geometry-modulated dislocation, intrinsic, and precipitation strengthening. Ductility anisotropy originates from columnar grain-loading direction coupling: TD tension induces intergranular fracture via premature strain localization at grain boundaries, while BD tension promotes homogeneous deformation and transgranular fracture.",

keywords = "In-situ EBSD, IN718, Laser powder bed fusion, Mechanical anisotropy",

author = "Ziyi Ding and Taiqing Deng and Xuewen Li and Kesong Miao and Xiaojun Wang and Guohua Fan",

note = "Publisher Copyright: {\textcopyright} 2026 Elsevier B.V.",

year = "2026",

month = nov,

doi = "10.1016/j.msea.2026.150943",

language = "英语",

volume = "975",

journal = "Materials Science and Engineering: A",

issn = "0921-5093",

publisher = "Elsevier Ltd",

}

TY - JOUR

T1 - Grain geometry dominated mechanical anisotropy in laser powder bed fused IN718 alloy

T2 - Insights from in-situ EBSD and DIC

AU - Ding, Ziyi

AU - Deng, Taiqing

AU - Li, Xuewen

AU - Miao, Kesong

AU - Wang, Xiaojun

AU - Fan, Guohua

PY - 2026/11

Y1 - 2026/11

N2 - This study reveals grain geometry-dominated mechanical anisotropy in laser powder bed fusion (LPBF) IN718 via in-situ EBSD and DIC. Despite a nearly random crystallographic orientation, the alloy exhibits significant strength and ductility anisotropy: transverse direction (TD) yield strength exceeds build direction (BD) yield strength by 136 MPa, whereas the uniform elongation is 28.2% lower. Through quantitative analysis of lattice rotation behaviors in grains of varying orientations, sizes, and aspect ratios during early deformation, we introduce an anisotropy coefficient (Ka) quantifying grain size and aspect ratio effects on lattice rotation. Modified strengthening models incorporating Ka demonstrate that strength anisotropy primarily arises from geometry-modulated dislocation, intrinsic, and precipitation strengthening. Ductility anisotropy originates from columnar grain-loading direction coupling: TD tension induces intergranular fracture via premature strain localization at grain boundaries, while BD tension promotes homogeneous deformation and transgranular fracture.

AB - This study reveals grain geometry-dominated mechanical anisotropy in laser powder bed fusion (LPBF) IN718 via in-situ EBSD and DIC. Despite a nearly random crystallographic orientation, the alloy exhibits significant strength and ductility anisotropy: transverse direction (TD) yield strength exceeds build direction (BD) yield strength by 136 MPa, whereas the uniform elongation is 28.2% lower. Through quantitative analysis of lattice rotation behaviors in grains of varying orientations, sizes, and aspect ratios during early deformation, we introduce an anisotropy coefficient (Ka) quantifying grain size and aspect ratio effects on lattice rotation. Modified strengthening models incorporating Ka demonstrate that strength anisotropy primarily arises from geometry-modulated dislocation, intrinsic, and precipitation strengthening. Ductility anisotropy originates from columnar grain-loading direction coupling: TD tension induces intergranular fracture via premature strain localization at grain boundaries, while BD tension promotes homogeneous deformation and transgranular fracture.

KW - In-situ EBSD

KW - IN718

KW - Laser powder bed fusion

KW - Mechanical anisotropy

UR - https://www.scopus.com/pages/publications/105047314624

U2 - 10.1016/j.msea.2026.150943

DO - 10.1016/j.msea.2026.150943

M3 - 文章

AN - SCOPUS:105047314624

SN - 0921-5093

VL - 975

JO - Materials Science and Engineering: A

JF - Materials Science and Engineering: A

M1 - 150943

ER -

Grain geometry dominated mechanical anisotropy in laser powder bed fused IN718 alloy: Insights from in-situ EBSD and DIC

Abstract

Keywords

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