Extreme-high-speed laser cladding (EHLC) technology offers a promising and cost-effective approach for fabricating thin high entropy alloy (HEA) coatings. The integration of EHLC with laser shock peening (LSP) offers an opportunity to enhance the performance of HEAs, thus broadening their potential applications. This study validates LSP as an effective post-treatment for CoCrFeMnNi HEA coatings deposited via EHLC. The impact of LSP on the microstructural characteristics, along with the corrosion and wear resistance of the EHLC HEA coatings, was meticulously evaluated. The results illustrated that LSP promoted dynamic recrystallization within EHLC HEA coatings, effectively reducing grain size and introducing high-density dislocation structures. With increasing LSP impacts, the average grain size of the coating reduced from 22.39 μm to 13.39 μm, while the impact depth of LSP significantly surpassed the thickness of the coatings (∼200 μm). Simultaneously, the residual stress in the EHLC HEA coating shifted from a tensile to a compressive state, peaking at −141.5 MPa. Subjecting the coatings to four LSP impacts resulted in a 51.9 % increase in microhardness, achieving 341.8 HV. The improvement of microstructure and the adjustment of residual stress are the main factors for improving the wear and corrosion resistance of EHLC HEA coatings. This research presents new strategies for the microstructural control and performance enhancement of HEA coatings deposited by EHLC.

中文翻译：

---

通过激光冲击强化极高速激光熔覆CoCrFeMnNi涂层的微观结构和性能


极高速激光熔覆 (EHLC) 技术为制造薄的高熵合金 (HEA) 涂层提供了一种有前途且经济高效的方法。 EHLC 与激光冲击喷丸 (LSP) 的集成提供了增强 HEA 性能的机会，从而拓宽了其潜在应用。这项研究验证了 LSP 是一种通过 EHLC 沉积的 CoCrFeMnNi HEA 涂层的有效后处理方法。仔细评估了 LSP 对 EHLC HEA 涂层的微观结构特征以及耐腐蚀性和耐磨性的影响。结果表明，LSP 促进了 EHLC HEA 涂层内的动态再结晶，有效减小晶粒尺寸并引入高密度位错结构。随着LSP冲击的增加，涂层的平均晶粒尺寸从22.39μm减小到13.39μm，而LSP的冲击深度显着超过涂层的厚度（∼200μm）。同时，EHLC HEA 涂层中的残余应力从拉伸状态转变为压缩状态，峰值为-141.5MPa。对涂层进行四次 LSP 冲击后，显微硬度提高了 51.9%，达到 341.8 HV。显微组织的改善和残余应力的调整是提高EHLC HEA涂层耐磨性和耐腐蚀性能的主要因素。这项研究提出了 EHLC 沉积的 HEA 涂层的微观结构控制和性能增强的新策略。