Cathode electrophoretic technology for bonded NdFeB permanent magnet
(1.重庆市重庆科技学院冶金与材料工程学院2.重庆市重庆大学材料科学与工程学院3.Eighth Research Institute of Nuclear Industry, Shanghai 201800, China4.Institute of Materials Science and Engineering, Shanghai University, Shanghai 200072, China5.Department of Materials Science and Technology, Shanghai University, Shanghai 200072, China)
Abstract: The bonded NdFeB permanent magnet was painted by cathode electrophoretic technology. The effect of technological parameters on the thickness of the layer was researched. The optimum voltage, time, electrophoresis temperature, area-ratio and spacing between cathode and anode are 220-250 V, 2-3 min, 25-32 ℃, 7-10 cm and (2-4)∶1, respectively. After treated under optimum conditions, the excellent corrosion resistance of the bonded magnet is achieved, with temperature and humidity resistant time of 468 h, brine-fast resistant time of 48 h. The cathode electrophoretic technology and treating process were successfully applied to produce bonded magnets with mass capacity of tens of million pieces per year.
Key words: bonded NdFeB magnets; cathode electrophoretic technology; layer thickness; technological parameters