Mechanical, materials, and physicochemical effects on the high-temperature tribological behaviour of laser additive manufacturing AlCoCrFeNi_2.1 eutectic high-entropy alloys

ABSTRACT

The AlCoCrFeNi_2.1 eutectic high-entropy alloys (EHEAs) were prepared using selective laser melting (SLM) to study the tribological properties at high temperatures, focusing on the complex mechanism of the friction process. The density of the SLM EHEAs is 99.70%. The lamellar and cellular structures are unevenly distributed at different locations. In situ XRD demonstrated the transition from BCC to FCC with increasing temperature. A large number of B2 particles are distributed in the BCC matrix. The fluctuation of the friction coefficient is closely related to the shape and size of the wear debris. The hardness of the alloy is ∼105 HV at 1000 °C. The wear rate first increases and then decreases with increasing temperature. The maximum thickness of the oxide film is 13.52 μm at 1000 °C and exhibits delamination. The combination of mechanical, materials and physicochemical effects during friction contributes to the excellent high temperature wear resistance.

KEYWORDS:

• Eutectic high-entropy alloys
• laser additive manufacturing
• high temperature oxidation
• friction mechanism

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Natural Science Foundation of China: [grant no 52075360 and 52105389]; the Primary Research and Development Plan of Shanxi Province [grant no 202102050201009]. Liwei Lan would like to thank the support of the China Scholarship Council.