超声振动辅助激光定向能量沉积 CoCrFeNiTi 高熵合金涂层：热与力学表征

High entropy alloys (HEAs) being the promising coating materials have emerged as advantageous due to their exceptional mechanical superiority, thermal stability, and corrosion resistance. Laser directed energy deposition (LDED) is among the favorable method of utilizing HEA coatings due to design versatility. Conventional LDED frequently encounters challenges including higher temperature gradients, rapid cooling rates, and inadequate regulation of microstructural development which can result in microstructural inhomogeneity, and defects such as micropores, lack of fusion and cracks. Ultrasonic vibration-assisted (UV-A) LDED has been found advantageous in boosting melt pool fluidity, facilitating grain refinement and heat distribution via acoustic streaming and cavitation. However, insignificant studies have been conducted on the HEA coatings for performance improvement through processing strategies. Therefore, this work intends to incorporate ultrasonic vibration to examine thermal, mechanical, and morphological attributes of CoCrFeNiTi HEA coatings. The dynamic changes of temperature in the molten pool were recorded during the experiment. With the assistance of ultrasonic vibration, molten pool peak center temperature was obtained higher in HEA coatings with reduced thermal gradient and cooling rate. The solidification dynamics were later analyzed via nano hardness and wear test, which highlighted the changes in localized mechanical characteristics and surface durability of the coatings. The attained results demonstrated an improved mechanical property. Morphological analysis was conducted through scanning electron microscope (SEM), which confirmed significant morphological enhancement. © 2026 The Authors. Published by ELSEVIER Ltd. This is an open access article under the CC BY-NC-ND license ( https://creativecommons.org/licenses/by-nc-nd/4.0 ) Peer-review under responsibility of the scientific committee of the NAMRI/SME.