Enhanced Surface Properties of the Al0.65CoCrFeNi High-Entropy Alloy via Laser Remelting

Abstract

The laser remelting technique was applied to the surface modification of the Al0.65CoCrFeNi high-entropy alloy (HEA) to further advance its mechanical potential. The microstructure of the remelted layer was refined from coarse dendritic to submicron-scale basket weave compared with the as-cast substrate, resulting in a 1.8-time increase in Vickers microhardness. The nanoindentation tests indicated that the nanohardness of the remelted layer was higher than that of each phase in the substrate. Meanwhile, the remelted layer retained considerable plasticity, as evidenced by its high Wp/Wt ratio (0.763) and strain hardening exponent (0.302). Additionally, adhesive wear prevailed on the substrate, while only abrasive wear features were observed on the remelted layer. Accordingly, the average friction coefficient and the wear rate of the remelted layer were minimized by 23% and 80%, respectively, compared with the substrate. Our findings explored an industrialized method to enhance the surface properties of the Al0.65CoCrFeNi HEA and also provided some helpful references for its laser additive manufacturing.

He-ion Irradiation Effects on the Microstructures and Mechanical Properties of the Ti-Zr-Hf-V-Ta Low-Activation High-Entropy Alloys

“…In the process of pursuing high-performance materials, the high-entropy alloys (HEAs) [ 21 ] were introduced. The preeminent properties (such as high strength [ 22 , 23 ], good corrosion resistance [ 24 , 25 , 26 ], fine tribological properties [ 27 , 28 ], remarkable softening resistance [ 29 , 30 ], and outstanding irradiation tolerance [ 1 , 2 , 5 , 31 ], etc.) enhance the application competitiveness of HEAs under extreme environments.…”

Achieving Excellent Strength-Ductility Balance in Single-Phase CoCrNiV Multi-Principal Element Alloy

“…The volume mismatch was caused by the difference of atomic size, which led to serious lattice distortion effect and hindered the dislocation movement to strengthen the materials [18][19][20]. For instance, the addition of elements such as C [21,22], Ti [23], Al [23][24][25], Mo [26,27], and others to CoCrNi or CoCrFeMnNi MPEAs can significantly improve the mechanical properties of the alloys. The addition of Al element to the CoCrNi alloy resulted in the formation of (CoCrNi) 87 Al 13 .…”