摘要
为了提高NdFeB磁体的耐蚀性,并验证磷化膜的组成,以自制的磷化液在NdFeB永磁体表面进行磷化处理,并采用SEM观测了采用不同表调剂处理NdFeB永磁体表面所形成的磁化膜微观形貌,测试分析了磷化膜的抗腐蚀性能;采用EDS、XRD、ICP-AES等对磷化膜进行了研究。结果表明:采用钛系表调剂可以在烧结NdFeB磁体表面获得均匀密实的磷化膜,并具有较强的耐腐蚀性;采用锌系磷化液在烧结NdFeB磁体表面进行磷化处理形成的磷化膜的组成与在钢铁基体上形成磷化膜的相组成相同,仍然是Zn3(PO4)2.4H2O及Zn2Fe(PO4)2.4H2O;磷化过程中,Nd参加了反应,形成沉渣进入磷化液中。
The phosphating solutions were developed to prepare phosphating films on NdFeB permanent magnet so as to increase the corrosion resistance.Thus the phosphating of the NdFeB permanent magnet was separately performed in a titanium series phosphating solution and a zinc series phosphating solution.The microstructures of the resulting phosphaing films were observed using a scanning electron microscope.The anticorrosion ability of the phosphating films was evaluated using pitting of CuSO4 solution.Besides,energy dispersive spectrometry and X-ray diffraction were performed to analyze the elemental composition and crystal structures of the phosphating films.It was found that a uniform and compact phosphating film was formed on the surface of the NdFeB permanent magnet treated with the Ti-type surface-conditioning agent,and this phosphating film had good corrosion resistance.The phosphating film formed on the NdFeB permanent magnet treated with the Ti-type surface-conditioning agent had the same crystal structure as that of the phosphating film on iron and steel substrate,i.e.,this phosphating film was composed of Zn3(PO4)2·4H2O and Zn2Fe(PO4)2·4H2O.The result of energy dispersive spectrometric analysis showed that Nd was present in the zinc phosphating bath,indicating that Nd in the permanent magnet took part in chemical reaction during the phosphating process and was transferred into the phosphating solution.Besides,no Nd was detected in the phosphating film after being treated with the phosphating solution,and the Ti-type surface-conditioning agent had stronger adjusting ability than the organic acid adjuster,corresponding well to the better anticorrosion ability of the NdFeB permanent magnet treated by the Ti-type surface-conditioning agent.
出处
《材料保护》
CAS
CSCD
北大核心
2007年第3期30-32,共3页
Materials Protection
关键词
NDFEB永磁体
磷化处理
磷化膜
微观形貌
耐蚀性能
NdFeB permanent magnet
phosphating
phosphating film
microstructure
corrosion resistance
