Fe-Ni-B-Si-Nb系非晶纳米晶复合涂层
(1. 上海工程技术大学 材料工程学院，上海 201620；
2. 上海交通大学 上海市激光制造与材料改性重点实验室，上海 200240)
摘 要: 采用激光熔覆和重熔的方法在低碳钢CCS-B上制备Fe-Ni-Si-B-Nb系非晶纳米晶复合涂层。利用X射线衍射、扫描电镜、EDAX能谱及透射电镜分析涂层的物相、组织结构，运用显微硬度计、纳米压痕仪及摩擦磨损试验机研究涂层的显微硬度分布、微观力学性能及摩擦磨损性能。结果表明：熔覆层的组织由表面至基体分为非晶纳米晶复合区、熔覆层与基体，其中，复合区为Fe2B、γ-(Fe, Ni)多晶和非晶相的混合组织；涂层的最高显微硬度达到了1 369 HV；涂层的平均摩擦因数为0.275；涂层的主要磨损形式是磨粒磨损和粘着磨损，具有良好的摩擦磨损性能。
关键字: 激光熔覆；Fe-Ni- B- Si-Nb；树枝晶；摩擦磨损
prepared by laser cladding and remelting
（1. School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620, China;
2. Shanghai Key Laboratory of Material Laser Processing and Modification,
Shanghai Jiaotong University, Shanghai, 200240, China）
Abstract:The Fe-Ni-B-Si-Nb amorphous composite coating was fabricated on the CCS-B mild steel by laser cladding and laser remelting. The phases, microstructure and impacts on glasses forming ability of the amorphous coatings were studied using X-ray diffractometer, scan electron microscope, EDAX energy spectrometer and transmission electron microscope. The microhardness, micro mechanical properties and wear resistance were studied by microhardness tester, nanoindentor and friction wear testing machine. The results show that the microstructure of coating consists of amorphous composite zone, original cladding zone and base metal. The amorphous composite zone consists of Fe2B, γ-(Fe, Ni) and amorphous phase. The highest hardness of coating is 1 369 HV and the average fraction coefficient is 0.275. Suppressing the crystalline phases with simple structure and promoting the crystalline phases with complex structure are good for fabricating the amorphous phase.
Key words: laser cladding; Fe-Ni- B- Si-Nb; dendrite; wear
