硅烷化处理对烧结钕铁硼永磁材料耐腐蚀性能的影响  

Effect of silanization treatment on corrosion resistance of sintered NdFeB permanent magnets

作　　者：张浩 张鹏杰[3,2] 曹玉杰 刘家琴 衣晓飞 陈静武[2] 吴玉程 

机构地区：[1]合肥工业大学工业与装备技术研究院,安徽合肥230009 [2]稀土永磁材料国家重点实验室(安徽大地熊新材料股份有限公司),安徽合肥231500 [3]合肥工业大学材料科学与工程学院,安徽合肥230009

出　　处：《材料热处理学报》2017年第12期70-76,共7页Transactions of Materials and Heat Treatment

基　　金：中国博士后科学基金(2017M612065);安徽省重点研究与发展计划项目(1704a0902020)

摘　　要：采用环境友好的硅烷化处理技术在烧结钕铁硼磁体表面制备一层硅烷转化膜,对烧结钕铁硼磁体进行暂时性防护。采用正交试验对过程中的工艺参数进行优化。采用冷场发射扫描电子显微镜(SEM)、拉力试验机、动电位极化曲线及中性盐雾试验(NSS)对所制备的硅烷转化膜的形貌、膜/基体之间结合力以及耐腐蚀性能进行研究。结果表明:硅烷转化膜均匀的涂覆在烧结Nd Fe B磁体表面,涂层致密性高、无孔隙、裂纹等缺陷。硅烷转化膜与基体之间的膜/基结合力强度可达14.14 MPa。薄膜耐中性盐雾试验可达12 h,硅烷转化膜在固化过程中醇基之间脱水缩合反应使硅烷转化膜表面形成具有不同交联密度的区域,在Na Cl溶液中交联密度低的区域首先水解溶解是造成磁体表面硅烷转化膜腐蚀失效的主要原因。An environmentally friendly silane conversion film was prepared on NdFeB substrate surface by silane technology to improve the corrosion resistance of the sintered NdFeB magnet. The parameters of deposition process were optimized by orthogonal experimental design. The morphology and bonding force between coating and substrate of the silane conversion film were studied by means of scanning electron microscopy（ SEM） and tensile testing machine. The corrosion resistance of the silane conversion film was studied by potentiodynamic polarization curve test and neutral salt spray test（ NSS）. The results show that the silane conversion film is uniformly coated on the sintered NdFeB magnetic surface with high density,and no porosity and crack can be observed. The bonding force between the silane conversion film and substrate is up to 14. 14 MPa. The neutral salt spray test of the silane conversion film can reach 12 h. There are different crosslinking density area formed in the surface of the silane conversion film due to the alcohol-based dehydration and condensation reactions,and the low crosslinking density area firstly dissolved hydrolysis is the main reason of the corrosion failure of the silane conversion film in Na Cl solution.

关 键 词：烧结钕铁硼 永磁材料 硅烷转化膜 耐腐蚀性能 腐蚀机理 

分 类 号：TG174.444[金属学及工艺—金属表面处理]