Crack inhibition and grain refinement in laser directed energy deposition of high-γ' Ni3Al-based superalloys via nanosized HfB2 addition

Fangdong Xu; Meng Guo; Runqi Gao; Dezhi Chen; Bin Gan; Ruirun Chen

doi:10.1016/j.matchar.2026.116516

Crack inhibition and grain refinement in laser directed energy deposition of high-γ' Ni₃Al-based superalloys via nanosized HfB₂ addition

Fangdong Xu
, Meng Guo
, Runqi Gao
, Dezhi Chen^*
, Bin Gan
, Ruirun Chen

^*Corresponding author for this work

School of Materials Science and Engineering

Harbin Institute of Technology
Suzhou Laboratory
Trinity College Dublin

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

Abstract

Crack-free specimens of a high-γ' Ni₃Al-based superalloy (MX246A) are manufactured by laser directed energy deposition (LDED) via incorporating HfB₂ nanoparticles. In the original MX246A specimens, cracks propagated intergranularly along columnar grain boundaries enriched with low-melting-point elements. The addition of 0.5 wt% HfB₂ (0.5HfB₂) effectively suppressed cracking by narrowing the terminal solidification temperature range and modifying solute segregation behavior. Meanwhile, HfB₂ promoted grain refinement, reducing the average grain size from 57.5 μm to 32.5 μm, and increased the fraction of low-angle grain boundaries from 13.2% to 22.1%. As a result, the 0.5HfB₂ sample exhibited superior mechanical properties. This approach improves the weldability of high-γ' Ni₃Al-based superalloys and offers a general strategy for the additive manufacturing of γ'-strengthened superalloys components.

Original language	English
Article number	116516
Journal	Materials Characterization
Volume	237
DOIs	https://doi.org/10.1016/j.matchar.2026.116516
State	Published - Jul 2026

Keywords

Crack
HfB
LDED
NiAl-based superalloy

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10.1016/j.matchar.2026.116516

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@article{62e0c7927a494428ac32ccd62601b86b,

title = "Crack inhibition and grain refinement in laser directed energy deposition of high-γ' Ni3Al-based superalloys via nanosized HfB2 addition",

abstract = "Crack-free specimens of a high-γ' Ni3Al-based superalloy (MX246A) are manufactured by laser directed energy deposition (LDED) via incorporating HfB2 nanoparticles. In the original MX246A specimens, cracks propagated intergranularly along columnar grain boundaries enriched with low-melting-point elements. The addition of 0.5 wt\% HfB2 (0.5HfB2) effectively suppressed cracking by narrowing the terminal solidification temperature range and modifying solute segregation behavior. Meanwhile, HfB2 promoted grain refinement, reducing the average grain size from 57.5 μm to 32.5 μm, and increased the fraction of low-angle grain boundaries from 13.2\% to 22.1\%. As a result, the 0.5HfB2 sample exhibited superior mechanical properties. This approach improves the weldability of high-γ' Ni3Al-based superalloys and offers a general strategy for the additive manufacturing of γ'-strengthened superalloys components.",

keywords = "Crack, HfB, LDED, NiAl-based superalloy",

author = "Fangdong Xu and Meng Guo and Runqi Gao and Dezhi Chen and Bin Gan and Ruirun Chen",

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

year = "2026",

month = jul,

doi = "10.1016/j.matchar.2026.116516",

language = "英语",

volume = "237",

journal = "Materials Characterization",

issn = "1044-5803",

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TY - JOUR

T1 - Crack inhibition and grain refinement in laser directed energy deposition of high-γ' Ni3Al-based superalloys via nanosized HfB2 addition

AU - Xu, Fangdong

AU - Guo, Meng

AU - Gao, Runqi

AU - Chen, Dezhi

AU - Gan, Bin

AU - Chen, Ruirun

PY - 2026/7

Y1 - 2026/7

N2 - Crack-free specimens of a high-γ' Ni3Al-based superalloy (MX246A) are manufactured by laser directed energy deposition (LDED) via incorporating HfB2 nanoparticles. In the original MX246A specimens, cracks propagated intergranularly along columnar grain boundaries enriched with low-melting-point elements. The addition of 0.5 wt% HfB2 (0.5HfB2) effectively suppressed cracking by narrowing the terminal solidification temperature range and modifying solute segregation behavior. Meanwhile, HfB2 promoted grain refinement, reducing the average grain size from 57.5 μm to 32.5 μm, and increased the fraction of low-angle grain boundaries from 13.2% to 22.1%. As a result, the 0.5HfB2 sample exhibited superior mechanical properties. This approach improves the weldability of high-γ' Ni3Al-based superalloys and offers a general strategy for the additive manufacturing of γ'-strengthened superalloys components.

AB - Crack-free specimens of a high-γ' Ni3Al-based superalloy (MX246A) are manufactured by laser directed energy deposition (LDED) via incorporating HfB2 nanoparticles. In the original MX246A specimens, cracks propagated intergranularly along columnar grain boundaries enriched with low-melting-point elements. The addition of 0.5 wt% HfB2 (0.5HfB2) effectively suppressed cracking by narrowing the terminal solidification temperature range and modifying solute segregation behavior. Meanwhile, HfB2 promoted grain refinement, reducing the average grain size from 57.5 μm to 32.5 μm, and increased the fraction of low-angle grain boundaries from 13.2% to 22.1%. As a result, the 0.5HfB2 sample exhibited superior mechanical properties. This approach improves the weldability of high-γ' Ni3Al-based superalloys and offers a general strategy for the additive manufacturing of γ'-strengthened superalloys components.

KW - Crack

KW - HfB

KW - LDED

KW - NiAl-based superalloy

UR - https://www.scopus.com/pages/publications/105039315319

U2 - 10.1016/j.matchar.2026.116516

DO - 10.1016/j.matchar.2026.116516

M3 - 文章

AN - SCOPUS:105039315319

SN - 1044-5803

VL - 237

JO - Materials Characterization

JF - Materials Characterization

M1 - 116516

ER -

Crack inhibition and grain refinement in laser directed energy deposition of high-γ' Ni₃Al-based superalloys via nanosized HfB₂ addition

Abstract

Keywords

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