Transport Properties of Equiatomic CoCrFeNi High-Entropy Alloy with a Single-Phase Face-Centered Cubic Structure

• Published in: Crystals (Basel) Vol. 13; no. 11; p. 1567
• Main Authors: Bykov, Victor A., Kulikova, Tatyana V., Sipatov, Ivan S., Sterkhov, Eugene V., Kovalenko, Darya A., Ryltsev, Roman E.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-11-2023
• Subjects: Alloys; Annealing; CoCrFeNi alloy; differential scanning calorimetry; Diffusivity; dilatometry; Electric arc melting; Electric properties; Heat conductivity; Heat transfer; High entropy alloys; Homogenization; Investigations; Lasers; Nickel chromium alloys; Physical properties; short-range ordering; Solid solutions; Solidification; Specialty metals industry; Specific heat; specific heat capacity; Temperature; Temperature dependence; Thermal conductivity; Thermal diffusivity; Thermal expansion; Thermal properties; Thermophysical properties; Transport properties; Germany
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst13111567

The key thermophysical properties necessary for the successful design and use of CoCrFeNi alloy in thermophysical applications have been measured experimentally, and the results have been compared with literature values and results previously obtained for commercial Ni-Cr alloys and equiatomic CoCrFeNi alloy. In particular, the thermal diffusivity, coefficient of thermal expansion (CTE), and specific heat capacity were measured for the as-cast and homogenized equiatomic CoCrFeNi alloy over a temperature range allowing the thermal conductivity to be calculated up to 1173 K. The thermal conductivity and thermal diffusivity of the equiatomic CoCrFeNi alloy were found to deviate from monotonic behavior in the temperature range from 773 to 1100 K. Such a deviation was previously observed in the behavior of the temperature dependence of CTE and specific heat capacity of the equiatomic CoCrFeNi alloy. The non-linear behavior is primarily the result of order/disorder phenomena for the as-cast and homogenized sample, as well as non-equilibrium solidification under arc melting conditions for the as-cast sample. The measured data of thermophysical properties are provided for thermally differently treated samples, and it is shown that there is a difference in the behavior of the temperature dependences of CTE, thermal diffusivity, and heat capacity.