Influence of Annealing Treatment on the Microstructure and Mechanical Properties of Cold-Sprayed CoCrFeNiMn High Entropy Alloy

Akisin, Cletus J.; Bennett, Chris J.; Venturi, Federico; Hussain, Tanvir

Abstract

In this study, we developed a ~ 2 mm thick deposit of CoCrFeNiMn high entropy alloy (HEA) from cold spray. After cold-spraying, annealing at 600, 800 and 1000 °C for 5 hrs was conducted to improve and consolidate the microstructure. The influence of the annealing treatment on the microstructure, hardness and tensile strength of the HEA deposit was studied. The results showed that annealing treatment increased the fraction of metallurgical bonded areas due to diffusion, which resulted in enhanced mechanical performances of the deposit. The examined fractured surfaces of the tensile test samples revealed that the annealing treatment changed the failure behavior of the as-sprayed deposit from mostly particle-particle interface failure to void coalescence (ductile failure). Interestingly, a distinct microstructure was observed for the deposited annealed at 600 °C; a partially recrystallized microstructure with a small volume fraction of Cr-rich phase formed along grain boundaries, whereas fully recrystallized microstructure at higher two temperatures. The strengthening effect of partial recrystallisation, with a small volume fraction of the Cr-rich phase led to a greater reduced modulus and tensile strength (~196.7 GPa and 51.7 MPa) of the deposit annealed at 600 °C when compared with that annealed at 800 °C (~182.5 GPa and 43.6 MPa). It is believed that the small volume fraction of the Cr-rich phase partly constrained the deformation of the surrounding FCC HEA matrix during mechanical loading, leading to better mechanical properties as compared to the deposit annealed at 800 °C.

Citation

Akisin, C. J., Bennett, C. J., Venturi, F., & Hussain, T. (2024). Influence of Annealing Treatment on the Microstructure and Mechanical Properties of Cold-Sprayed CoCrFeNiMn High Entropy Alloy. Journal of Thermal Spray Technology, 34(1), 139-163. https://doi.org/10.1007/s11666-024-01889-y

• Journal Article Type: Article
• Acceptance Date: Oct 30, 2024
• Online Publication Date: Nov 27, 2024
• Publication Date: Nov 27, 2024
• Deposit Date: Apr 14, 2025
• Publicly Available Date: Apr 14, 2025
• Journal: Journal of Thermal Spray Technology
• Print ISSN: 1059-9630
• Electronic ISSN: 1544-1016
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 34
• Issue: 1
• Pages: 139-163
• DOI: https://doi.org/10.1007/s11666-024-01889-y
• Keywords: cold spray additive manufacturing, dynamic recrystallisation, high-entropy alloys, microstructure, mechanical property, precipitation
• Public URL: https://nottingham-repository.worktribe.com/output/42839189
• Publisher URL: https://link.springer.com/article/10.1007/s11666-024-01889-y
• Additional Information: Received: 29 July 2024; Revised: 27 October 2024; Accepted: 30 October 2024; First Online: 27 November 2024