Mössbauer and Ultrasonic Study of the As-Cast High-Entropy Al$_x$CuCrCoNiFe Alloys

Abstract

Determination of the hyperfine-interaction parameters, acoustic and elastic properties of the high-entropy Al x CuCrCoNiFe alloys (HEAs) (x 1, 1.8) in the as-cast state is carried out with the use of Mössbauer spectroscopy, x-ray diffractometry and high-precision ultrasonic techniques. Wide distributions of both the hyperfine-magnetic fields on iron nuclei (5.0-36.3 T) and the isomer shifts ( 0.15-0.28 mm/s) are detected in the HEAs that is result of multiphase state and inhomogeneous short-range order in the phases. As shown, the as-cast Al x CuCrCoNiFe HEAs are acoustically and elastically inhomogeneous systems. Mean elastic moduli of the as-cast equimolar HEAs ( E 172.8 GPa, G 65.3 GPa, B 161.8 GPa) Ключевые слова: высокоэнтропийный сплав, ультразвук, упругие свой-ства, анизотропия упругости, эффект Мёссбауэра.

Properties of Invar alloy Fe‐30.9 % Ni‐1.23 % C after dispersion of structure by upsetting

“…The reduced elastic moduli of both standard Invar Fe‐(35–36) % Ni alloy and the carbon‐containing Invar Fe‐(29–30) % Ni–C alloys as compared to the f.c.c. Fe–Ni alloys with the Ni concentration behind the Invar composition is the distinguishing feature that indicates weakened stiffness of interatomic bond . It was established that all of the characteristics of elasticity of the studied Fe‐30.9 % Ni‐1.23 % C alloy behave similarly at plastic deformation, namely they decrease after upsetting with the strain e = 1.1, Fig.…”

Ultrasonic Investigation of High-Entropy Al$_{0.5}$CoCrCuFeNi Alloy at Low Temperature

“…The results obtained at 300 K are shown in Table 3. As can be seen, the values of the elastic characteristics for the HEA1 and HEA2 samples are noticeably differ due to the certain elastic anisotropy, which is also supplemented by the spatial heterogeneity of this material [12].…”