Abstract In this research, ultrasonic impact treatment was introduced on the surfaces of laser cladding Al0.5CoCrFeMnNi high entropy alloy coatings. The results showed that obvious solidification boundaries with some lamellar cluster and polygonal precipitations generated inside the cladding coatings. After UIT for one time, a thin impacted layer with obvious plastic deformation was formed. When treated for two times, many floccules formed near the surface while with the increase of impact times evident impact tracks were found on the surface of ultrasonic impact layer due to excessive plastic deformation. In addition, original precipitations located along the solidification boundaries were broken into small ones, and the particles inside the matrix were also cracked. The minimum surface roughness and maximum surface hardness of ultrasonic impact layers can be obtained for one impact time. XRD analysis indicated that Al0.5CoCrFeMnNi cladding coating was composed of single FCC phase while application of UIT technology did not change the phase structure of coatings. It also was noted that the weight losses of ultrasonic impact layers were lower than those of cladding coatings whilst the current density was decreased by 69.6%, 87% in the 3.5%NaCl and 1 mol/L NaOH solutions, respectively, indicating better corrosion resistance of impact layers.

中文翻译：

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超声冲击处理对激光熔覆Al0.5CoCrFeMnNi高熵合金涂层组织和性能的影响

摘要 本研究对激光熔覆Al0.5CoCrFeMnNi高熵合金涂层表面进行超声冲击处理。结果表明，熔覆层内部有明显的凝固边界，带有一些层状团簇和多边形析出物。UIT 一次后，形成一个薄的冲击层，具有明显的塑性变形。两次处理后，在表面附近形成了许多絮状物，而随着冲击次数的增加，超声冲击层表面由于塑性变形过大而出现明显的冲击痕迹。此外，沿着凝固边界的原始沉淀物被破碎成小颗粒，基体内部的颗粒也被破碎。一次冲击时间可获得超声波冲击层的最小表面粗糙度和最大表面硬度。XRD分析表明Al0.5CoCrFeMnNi包覆涂层由单一的FCC相组成，而UIT技术的应用并未改变涂层的相结构。还注意到超声波冲击层的重量损失低于熔覆涂层的重量损失，而电流密度在 3.5%NaCl 和 1 mol/L NaOH 溶液中分别降低了 69.6% 和 87%，表明具有更好的耐腐蚀性影响层。