真空退火对镀Al薄膜NdFeB磁体矫顽力和耐蚀性的影响  

Effect of vacuum annealing on coercivity and corrosion resistance of Al-coated NdFeB magnets

作　　者：胡方勤[1] 史丰锴 张青科 赵宇 肖涛 Hu Fangqin;Shi Fengkai;Zhang Qingke;Zhao Yu;Xiao Tao(Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo Zhejiang 315201,China;Hangzhou Permanent Magnet Group Co.,Ltd.,Hangzhou Zhejiang 311200,China)

机构地区：[1]中国科学院宁波材料技术与工程研究所,浙江宁波315201 [2]杭州永磁集团有限公司,浙江杭州311200

出　　处：《金属热处理》2022年第6期72-77,共6页Heat Treatment of Metals

基　　金：宁波市“科技创新2025”重大专项(2020Z045);浙江省重点研发计划(2020C05013)。

摘　　要：采用电弧离子镀技术在烧结NdFeB表面沉积一层Al薄膜,并进行真空退火热处理。利用扫描电镜、永磁材料测量系统、电化学工作站和盐雾试验箱等,研究了不同退火工艺对Al/NdFeB试样显微组织、磁性能和耐蚀性的影响。结果表明,随着退火温度的升高,矫顽力先升高后降低,550℃退火60 min时矫顽力最高,达到22.41 kOe,较镀态试样增幅7.6%,但耐蚀性有所降低;随着退火时间的增加,矫顽力先降低后升高,550℃退火5 min时矫顽力为22.16 kOe,且自腐蚀电流密度较基体NdFeB降低了1~2个数量级。550℃退火5 min试样具有较高的矫顽力和较好的耐蚀性能。Al coatings were deposited on the surface of sintered NdFeB by using arc ion plating and then subjected to vacuum annealing. Effect of different annealing processes on microstructure, magnetic properties and corrosion resistance of Al/NdFeB was investigated by means of scanning electron microscopy, permanent magnet material measurement system, electrochemical workstation and salt spray test chamber. The results show that the coercivity first increases and then decreases with the increase of annealing temperature, the highest coercivity of 22.41 kOe is obtained when annealed at 550 ℃ for 1 h, increasing by 7.6%, while the corrosion resistance decreases compared with the untreated magnet. With the increase of annealing time, the coercivity first decreases and then increases. When annealed at 550 ℃ for 5 min, the coercivity is 22.16 kOe, and the self-corrosion current density is 1-2 orders of magnitude lower than that of the matrix NdFeB. The specimens annealed at 550 ℃ for 5 min have higher coercivity and better corrosion resistance.

关 键 词：Al薄膜 烧结NDFEB 真空退火 矫顽力 耐蚀性 

分 类 号：TG156.1[金属学及工艺—热处理]