Joining of high-entropy ceramics (HEC) to Nb using CoFeCrNiCu high-entropy alloy as filler via spark plasma sintering

Rui Zhang; Gang Wang; Wei Wang; Yu Zhao; Rujie He; Caiwang Tan

doi:10.1016/j.vacuum.2026.115667

Joining of high-entropy ceramics (HEC) to Nb using CoFeCrNiCu high-entropy alloy as filler via spark plasma sintering

Rui Zhang
, Gang Wang^*
, Wei Wang
, Yu Zhao
, Rujie He
, Caiwang Tan

^*Corresponding author for this work

Anhui Polytechnic University
Key Laboratory of Additive Manufacturing (3D Printing) of Anhui Province
Anhui Technical College of Mechanical and Electrical Engineering
Beijing Institute of Technology
Harbin Institute of Technology

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

Abstract

The (TiZrHfNbTa)C high-entropy ceramic (HEC) and Nb were joined by spark plasma sintering, with CoFeCrNiCu high-entropy alloy serving as the filler material. The typical microstructure of the joint consists of HEC/FCC, Laves, Cu(s,s), and NbC. The impact of joining temperature and holding time on the microstructure, shear strength, and fracture path of the HEC/CoFeCrNiCu/Nb joints were systematically investigated. At the same time, the phase formation mechanism and microstructure evolution of the joint during SPS process are explained. The shear strength of the joint reached a maximum of 52 MPa at room temperature after holding at 1100 °C for 6 min. The high-entropy effect of the CoFeCrNiCu filler promotes the formation of the FCC phase in the central region of the joint. Additionally, due to the diffusion of Nb and C, a diffusion transition layer consisting of the Laves phase and NbC forms near the Nb side, contributing to the enhancement of the shear strength.

Original language	English
Article number	115667
Journal	Vacuum
Volume	254
DOIs	https://doi.org/10.1016/j.vacuum.2026.115667
Publication status	Published - Nov 2026
Externally published	Yes

Keywords

High entropy alloy
High-entropy carbide ceramic
Interface microstructure
Joining
Shear strength
Spark plasma sintering

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10.1016/j.vacuum.2026.115667

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@article{0d13538a26c54c3ba5d4d4eb6bf39190,

title = "Joining of high-entropy ceramics (HEC) to Nb using CoFeCrNiCu high-entropy alloy as filler via spark plasma sintering",

abstract = "The (TiZrHfNbTa)C high-entropy ceramic (HEC) and Nb were joined by spark plasma sintering, with CoFeCrNiCu high-entropy alloy serving as the filler material. The typical microstructure of the joint consists of HEC/FCC, Laves, Cu(s,s), and NbC. The impact of joining temperature and holding time on the microstructure, shear strength, and fracture path of the HEC/CoFeCrNiCu/Nb joints were systematically investigated. At the same time, the phase formation mechanism and microstructure evolution of the joint during SPS process are explained. The shear strength of the joint reached a maximum of 52 MPa at room temperature after holding at 1100 °C for 6 min. The high-entropy effect of the CoFeCrNiCu filler promotes the formation of the FCC phase in the central region of the joint. Additionally, due to the diffusion of Nb and C, a diffusion transition layer consisting of the Laves phase and NbC forms near the Nb side, contributing to the enhancement of the shear strength.",

keywords = "High entropy alloy, High-entropy carbide ceramic, Interface microstructure, Joining, Shear strength, Spark plasma sintering",

author = "Rui Zhang and Gang Wang and Wei Wang and Yu Zhao and Rujie He and Caiwang Tan",

note = "Publisher Copyright: {\textcopyright} 2026 Published by Elsevier Ltd.",

year = "2026",

month = nov,

doi = "10.1016/j.vacuum.2026.115667",

language = "English",

volume = "254",

journal = "Vacuum",

issn = "0042-207X",

publisher = "Elsevier Ltd.",

}

TY - JOUR

T1 - Joining of high-entropy ceramics (HEC) to Nb using CoFeCrNiCu high-entropy alloy as filler via spark plasma sintering

AU - Zhang, Rui

AU - Wang, Gang

AU - Wang, Wei

AU - Zhao, Yu

AU - He, Rujie

AU - Tan, Caiwang

PY - 2026/11

Y1 - 2026/11

N2 - The (TiZrHfNbTa)C high-entropy ceramic (HEC) and Nb were joined by spark plasma sintering, with CoFeCrNiCu high-entropy alloy serving as the filler material. The typical microstructure of the joint consists of HEC/FCC, Laves, Cu(s,s), and NbC. The impact of joining temperature and holding time on the microstructure, shear strength, and fracture path of the HEC/CoFeCrNiCu/Nb joints were systematically investigated. At the same time, the phase formation mechanism and microstructure evolution of the joint during SPS process are explained. The shear strength of the joint reached a maximum of 52 MPa at room temperature after holding at 1100 °C for 6 min. The high-entropy effect of the CoFeCrNiCu filler promotes the formation of the FCC phase in the central region of the joint. Additionally, due to the diffusion of Nb and C, a diffusion transition layer consisting of the Laves phase and NbC forms near the Nb side, contributing to the enhancement of the shear strength.

AB - The (TiZrHfNbTa)C high-entropy ceramic (HEC) and Nb were joined by spark plasma sintering, with CoFeCrNiCu high-entropy alloy serving as the filler material. The typical microstructure of the joint consists of HEC/FCC, Laves, Cu(s,s), and NbC. The impact of joining temperature and holding time on the microstructure, shear strength, and fracture path of the HEC/CoFeCrNiCu/Nb joints were systematically investigated. At the same time, the phase formation mechanism and microstructure evolution of the joint during SPS process are explained. The shear strength of the joint reached a maximum of 52 MPa at room temperature after holding at 1100 °C for 6 min. The high-entropy effect of the CoFeCrNiCu filler promotes the formation of the FCC phase in the central region of the joint. Additionally, due to the diffusion of Nb and C, a diffusion transition layer consisting of the Laves phase and NbC forms near the Nb side, contributing to the enhancement of the shear strength.

KW - High entropy alloy

KW - High-entropy carbide ceramic

KW - Interface microstructure

KW - Joining

KW - Shear strength

KW - Spark plasma sintering

UR - https://www.scopus.com/pages/publications/105045017023

U2 - 10.1016/j.vacuum.2026.115667

DO - 10.1016/j.vacuum.2026.115667

M3 - Article

AN - SCOPUS:105045017023

SN - 0042-207X

VL - 254

JO - Vacuum

JF - Vacuum

M1 - 115667

ER -

Joining of high-entropy ceramics (HEC) to Nb using CoFeCrNiCu high-entropy alloy as filler via spark plasma sintering

Abstract

Keywords

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