- [English]
- Ultrasonic Nanocrystal Surface Modification of 3D Interconnected Heterostructured Complex Concentrated Alloys Produced by Liquid Metal Dealloying: Microstructural Evolution and Wear Behavior
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Jumi Choi, Yeji Kim, Munsu Choi, Jae Hyuk Lee, Dong Jun Lee, Auezhan Amanov, Soo-Hyun Joo, Hyoung Seop Kim
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Received February 20, 2026 Accepted April 20, 2026 Published online April 21, 2026
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DOI: https://doi.org/10.4150/jpm.2026.00045
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 Abstract
- This study investigates the effects of ultrasonic nanocrystal surface modification (UNSM) on the microstructural evolution and tribological performance of a three-dimensional interconnected heterostructured compositionally complex alloy fabricated by liquid metal dealloying (LMD). The as-LMD microstructure comprises an interconnected Cu-rich phase and a CoCrFe-rich ligament phase. Electron backscatter diffraction reveals pronounced severe plastic deformation near the surface after UNSM, characterized by subgrain formation and increased intragranular misorientation. The kernel average misorientation distribution reveals a pronounced depth-dependent deformation gradient, with dislocations preferentially accumulating at the interphase boundaries. Vickers hardness increases from approximately 100–120 HV in the as-LMD condition to greater than 270 HV at the surface after UNSM, and the hardening effect remains detectable to a depth of approximately 500 μm. Compressive residual stresses are concentrated within the surface-adjacent ~50 μm. The solid ligament phase exhibits higher compressive residual stress than the Cu-rich phase, reflecting phase-dependent deformation accommodation and stress partitioning. Reciprocating wear tests show a narrower wear track, a markedly reduced wear depth, and a lower and more stable friction coefficient after UNSM. Microscopy shows oxide-layer cracking and delamination in the as-LMD condition, whereas the UNSM-treated surface exhibits minor abrasive wear of the tribo-film without delamination.
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