真空热处理对镀Al薄膜NdFeB磁体组织和耐蚀性的影响  

Influence of Vacuum Annealing on Microstructures and Corrosion Resistance of Al-Coated NdFeB Magnets

作　　者：孙宝玉[1,2] 巴德纯[1] 段永利 房也[1,2] 杨彬 岳向吉[1] 

机构地区：[1]东北大学机械工程与自动化学院,沈阳110004 [2]爱发科中北真空(沈阳)有限公司,沈阳110168 [3]沈阳中北通磁科技有限公司,沈阳110168

出　　处：《真空科学与技术学报》2011年第2期221-224,共4页Chinese Journal of Vacuum Science and Technology

摘　　要：用直流磁控溅射工艺,在NdFeB磁体表面镀Al薄膜,并对镀Al薄膜的磁体进行真空热处理,研究工艺、温度和时间对镀层成分、组织和性能的影响。结果表明:NdFeB镀Al薄膜磁体经650℃,10 min热处理后,综合性能最佳,Al膜层与Nd-FeB磁体在界面产生冶金结合,增强了界面结合力,又保持了Al膜层的完整性、连续性和良好耐蚀性。通过对样品微组织的观察发现,当热处理温度高于650℃时,Al膜层与基体之间产生互扩散,形成新的RFeAlB相,随着温度继续升高,新相的长大,破坏了Al膜层的完整性和连续性,产生许多微缺陷和裂纹,耐蚀性降低。The Al films were deposited by DC magnetron sputtering on surfaces of the NdFeB permanent magnets.The influence of the deposition conditions,including the annealing temperature and time,deposition time,on properties of the films was studied.Its microstructures and corrosion behavior were characterized with salt spray test,palarization curves,and scanning electron microscopy.The results show that the Al coating significantly improves corrosion resistance of the magnets,and that the annealing temperature and time strongly affect the microstructures at the interface of Al films and the magnet.After vacuum annealing at 650℃ for 10 min.,well-defined Al/NdFeB interface was observed with strong adhesion and high surface corrosion resistance.If annealing temperature is higher than 650℃,the interfacial diffusion resulted in formation of defects and new RNdFeB phase.Moreover,the roughened surface of Al film decreased its corrosion resistance.Possible mechanisms were tentatively discussed.

关 键 词：NDFEB 磁控溅射 Al薄膜 真空热处理 耐蚀性能 

分 类 号：TM273[一般工业技术—材料科学与工程]