锆合金表面Al_(0.2)CrFeNiCu_(1.5)高熵合金涂层的组织与性能研究  

Microstructure and Property of Al_(0.2)CrFeNiCu_(1.5)High Entropy Alloy Coating on Zirconium Alloy Surface

作　　者：陈志培 任晓娜 葛昌纯[1] CHEN Zhipei;REN Xiaona;GE Changchun(University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学,北京100083

出　　处：《原子能科学技术》2025年第2期429-435,共7页Atomic Energy Science and Technology

基　　金：国家自然科学基金(52371091)。

摘　　要：采用超高速激光熔覆技术在锆合金棒上成功制备了Al_(0.2)CrFeNiCu_(1.5)高熵合金涂层,涂层与基体具有良好的冶金结合,没有裂纹和气孔等缺陷。采用扫描电子显微镜对涂层进行了形貌和能谱分析,用显微维氏硬度计和电化学工作站对涂层的硬度和耐腐蚀性能进行了研究。结果表明:涂层底部与基体之间存在元素的相互扩散,热影响区宽约86μm,在其界面处可以观察到垂直生长的柱状晶。涂层组织主要由灰黑色的枝晶区和灰白色的枝晶间区组成。涂层成分均匀,硬度最高可达690 HV,高熵合金特有的固溶强化、晶格畸变和缓慢扩散效应是其具有高硬度的主要原因。涂层的自腐蚀电流密度为6.241×10^(-8) A/cm^(2),极化电阻为1.181×10^(6)Ω/cm^(2),阻抗为2.326×10^(6)Ω/cm^(2),Al_(0.2)CrFeNiCu_(1.5)高熵合金涂层提高了锆合金基体的耐腐蚀性能。It is an effective way to improve the accident tolerant capability of fuel cladding tube to prepare a reinforced coating on the surface of zirconium alloy.Laser cladding technology is one of the most commonly used methods to prepare high entropy alloy coatings.In this paper,high speed laser cladding technology with little influence on substrate heat was used to successfully prepare Al_(0.2)CrFeNiCu_(1.5)high entropy alloy coating on zirconium alloy rods with good metallurgical bonding to substrate and no defects such as cracks and pores.The microstructure of the surface and cross section of the coating was observed and analyzed by scanning electron microscope,the cross section hardness of the coating was studied by micro-Vickers hardness tester,and the corrosion resistance of the coating in 3.5%NaCl solution was studied by electrochemical workstation.The results show that there is mutual diffusion of elements between the bottom of the coating and the substrate,the heat affected zone of the substrate is small,about 86μm wide,and vertical columnar crystals can be observed at the interface.Heat dissipation is faster at the joint of the bottom of the coating and the substrate,the temperature gradient is large,and the value of G/R gradually decreases from the bottom to the top of the coating,so that the columnar crystal gradually changes to the equiaxed crystal.The coating is composed of grayblack dendrite region and gray-white interdendritic region,in which Fe and Cr elements are enriched in the dendritic region,Al and Ni elements are enriched in the interdendritic region,and Cu elements are enriched at the interface between the dendrites and dendrites.The cross section hardness of the coating is less different,up to 690 HV,about 1.53 times that of the substrate.The main reasons for the high hardness of high entropy alloys are solution strengthening,lattice distortion and slow diffusion.The coating has a wide passivation film,the self-corrosion potential is about-0.508 V,and the positive shift is about 1.723 V compa

关 键 词：激光熔覆 高熵合金涂层 耐腐蚀性能 

分 类 号：TL352[核科学技术—核技术及应用] TG174.4[金属学及工艺—金属表面处理]