Microstructure Evolution and Mechanical Properties of FeCoCrNiCuTi0.8 High-Entropy Alloy Prepared by Directional Solidification

Abstract

A CoCrCuFeNiTi0.8 high-entropy alloy was prepared using directional solidification techniques at different withdrawal rates (50 μm/s, 100 μm/s, 500 μm/s). The results showed that the microstructure was dendritic at all withdrawal rates. As the withdrawal rate increased, the dendrite orientation become uniform. Additionally, the accumulation of Cr and Ti elements at the solid/liquid interface caused the formation of dendrites. Through the measurement of the primary dendrite spacing (λ1) and the secondary dendrite spacing (λ2), it was concluded that the dendrite structure was obviously refined with the increase in the withdrawal rate to 500 μm/s. The maximum compressive strength reached 1449.8 MPa, and the maximum hardness was 520 HV. Moreover, the plastic strain of the alloy without directional solidification was 2.11%, while the plastic strain of directional solidification was 12.57% at 500 μm/s. It has been proved that directional solidification technology can effectively improve the mechanical properties of the CoCrCuFeNiTi0.8 high-entropy alloy.

CoxCrFeNiTi High-Entropy Alloys Prepared via Mechanical Alloying and Spark Plasma Sintering for Magnetron Sputtering Coatings

“…As indicated in the SEM microstructural analyses, no visible defects that could affect the integrity of the sample were detected. The presence of fine dendrites confirms that the developed material belongs to the high-entropy alloys domain [29][30][31]. This type of structure was also present in the CoCrFeNiTi equiatomic HEA and the Co 0.5 CrFeNiTi low-cobalt-content HEA.…”

Superconducting and normal-state properties of the high-entropy alloy Nb-Re-Hf-Zr-Ti investigated by muon spin relaxation and rotation

“…High entropy alloys (HEAs) are a class of multicomponent materials with outstanding mechanical, thermal, physical, and chemical properties [1,2]. HEAs are typically a solid solution containing more than five principal elements [3][4][5]. Configuration entropy (S) is also used as a parameter to define HEAs.…”

Effect of electron beam treatment on the structure and properties of AlCoCrFeNi high-entropy alloy

“…The idea of high-entropy alloys is that atoms of all elements are considered atoms of a dissolved substance, cause deformation of a crystal structure and improve thermodynamic stability of properties related to differences in atomic radii of components. It results in high entropy of a system to further manufacturing a material with unique properties, which are impossible in traditional micro-alloying techniques [8][9][10].…”