摘要
分别采用普通激光熔覆和高速激光熔覆工艺在镍基高温合金基体表面制备AlCoCrFeNi_(2.1)-YHf高熵合金涂层,研究了不同激光熔覆工艺下高熵涂层微观组织与成分演变,及其在1150℃时抗高温氧化机理.分别采用X射线衍射仪、扫描电子显微镜及透射电子显微镜对制备得到的2种涂层进行晶体结构、微观组织及元素组成表征,随后将试样置于在1150℃下进行100 h恒温氧化,期间记录不同时间点涂层重量增加情况并对截面微观组织及成分进行表征.试验结果表明,2种涂层均由FCC相组成,普通熔覆涂层存在明显的Nb,Y和Hf元素偏析,高速熔覆涂层组织结构更加细密均匀.氧化100 h后2类熔覆涂层氧化增重分别为1.76与0.91 mg/cm^(2),氧化膜增厚分别为7.568与3.535μm.此外,高速熔覆涂层拥有更加平直且完整的氧化膜及极少量的尖晶石生成,表现出优异的抗高温氧化性能.
AlCoCrFeNi_(2.1)-YHf high-entropy alloy coatings were synthesized on the surface of a nickel-based high-temperature alloy substrate by using ordinary laser melting and high-speed laser melting techniques.The study examined the microstructural and compositional evolution of the high-entropy bonded layer,as well as its resistance to high-temperature oxidation mechanism at 1150℃,under different laser melting processes conditions.The crystal structure,microstructure and elemental composition of the two types of coatings were characterized using X-ray diffractometer,scanning electron microscope,and transmission electron microscope.The specimen was subjected to constant temperature oxidation at 1150℃for a duration of 100 h.During this period,the increase in coating weight at different time points was systematically recorded.Additionally,the microstructure and composition of the cross-section were thoroughly characterized.The test results show that both coatings types are composed of FCC phases.Notably,the conventional Nb,Y and Hf elemental segregation in the ordinary fusion-coated coating,and a finer and more homogeneous microstructure organization in the high-speed fusion-coated coating.The oxidized weight gain of the two types of fusion-coated coatings after 100 h of oxidation is 1.76 and 0.91 mg/cm^(2),with corresponding oxide film thickness of 7.568μm and 3.535μm,respectively.In addition,the high-speed fusion-coated coatings exhibit a more straight and complete oxide film with minimal spinel formation,indicating excellent resistance to high-temperature oxidation performance.
作者
缪立圆
李向成
钱伟
花银群
蔡杰
MIAO Liyuan;LI Xiangcheng;QIAN Wei;HUA Yinqun;CAI Jie(Institute of Advanced Manufacturing and Modern Equipment Technology,Jiangsu University,Zhenjiang,Jiangsu 212013,China;School of Mechanical Engineering,Jiangsu University,Zhenjiang,Jiangsu 212013,China)
出处
《排灌机械工程学报》
北大核心
2025年第7期740-748,共9页
Journal of Drainage and Irrigation Machinery Engineering
关键词
激光熔覆
高熵涂层
微观结构
高温氧化
动力学曲线
laser cladding
high-entropy coating
microstructure
high-temperature oxidation
kinetics curves
