铬含量对FeCoCrxNiB高熵合金涂层氧化行为的影响

Effects of Chromium Content on Oxidation Behavior of FeCoCr_x NiB High-entropy Alloy Coatings

在45钢基体上用激光熔覆方法制备FeCoCr_xNiB（x=0.5~3）高熵合金涂层。不同Cr含量（原子数分数）的FeCoCr_xNiB高熵合金涂层在900℃下进行高温氧化实验,测定其氧化动力曲线,并采用XRD、SEM和EDS等方法分析氧化层结构和形貌。结果表明,不同Cr含量的FeCoCr_xNiB涂层氧化动力学曲线基本都符合抛物线规律。随着Cr含量的增加,FeCoCr_xNiB涂层的氧化膜由富Fe的氧化物逐渐向富Cr氧化物转变,并最终生成稳定、连续的Cr2O3氧化膜。富Fe的氧化物表面形貌为针状且较为疏松,而富Cr的氧化物则为较为致密颗粒状。涂层的抗氧化性能随Cr含量的增加而增强。当Cr含量超过x=2后,FeCoCr_xNiB涂层获得了较好的抗氧化性能。

FeCoCr_xNiB（x=0.5-3）high-entropy alloy coatings were prepared by laser cladding on 45 steel.The oxidation experiments of the FeCoCr_xNiB high-entropy alloy coating with different Cr ontent were performed at temperature of900 ℃,and the corresponding oxidation kinetics curves were tested.The structure and morphology of the oxide layer were studied by adopting the analytical methods,such as XRD,SEM,and EDS.The results show that FeCoCr_xNiB coatings obey the parabolic law.With increasing Cr content,the oxide film of the FeCoCr_xNiB coatings gradually changes from Fe-rich oxide to Cr-rich oxide,and finally generates a stable and continuous film of Cr2O3.The surface morphology of the Fe-rich oxide film is needle-like and loose,while the Cr-rich oxide film is granular-like and dense.The oxidation resistance of the FeCoCr_xNiB coatings is improved with increasing of Cr content.When the content of Cr is more than x=2,better antioxidant properties of the FeCoCr_xNiB coatings obtained.