【作者】 李军；

【导师】 刘颖；

【作者基本信息】 四川大学 ， 材料学， 2003， 硕士

【摘要】 为了充分发挥我国稀土资源优势，发展我国的NdFeB稀土永磁产业，本文比较系统地研究了高性价比的模压成型粘结NdFeB永磁体制备过程中的相关问题，包括高性价比快淬NdFeB磁粉制备、模压成型粘结NdFeB磁体制备、NdFeB磁粉特性对粘结磁体磁性能的影响、NdFeB磁体阴极电泳涂层工艺及其涂层对磁体抗蚀性的影响。 研究表明：制备钴含量低于5at％的Nd₁₁（FeCoZr）₈₃B₆磁粉的最佳工艺为：淬速28m／s，热处理为660℃×40Min；这种磁粉制成磁体后磁性能为：Br=667.4mT，Hcj=755kA／m，Hcb=443kA／m，（BH）_m=75kJ／m³；其性价比远高于MQP-B磁粉，完全能满足实际生产的需要。 通过对七种热固性环氧树脂粘结剂的比较发现，含有A型粘结剂的磁体抗压强度较高，含有E型粘结剂的磁体磁性能较高。从磁性能和抗压强度两方面考虑，选用A+E混合型粘结剂。磁体压制时合适的成型压力在7～11t／cm²之间，合适的保压时间在60S左右。改变磁体的压制方法能有效提高磁体的密度和磁性能。磁体固化一般在真空氛围下进行。所用粘结剂合适的固化温度是120℃，合适的固化时间是120Min，固化后磁体应该随炉冷却。 添加占磁粉重量的1‰～2‰之间的KH550硅烷偶联剂能改善磁粉与粘结剂的结合情况，使磁体的磁性能和抗压强度得到提高。添加适量润滑剂能提高磁体的密度和磁性能。合理的粒度搭配能有效提高磁体的密度和磁性能，磁选能使磁体的磁性能进一步得到提高。如果把粒度配合、二次压制、二次成型以及磁选结合起来，磁体的密度和磁性能能够显著得到提高。用MQP-B⁺磁粉可以得到磁能积高达110kJ／m³的各向同性粘结磁体。 粘结NdFeB磁体需要阴极电泳涂层以提高磁体的耐蚀性。经研究发现其最佳工艺为：电泳时漆液的温度应控制在28℃～30℃之间；电泳初期电压为90V，沉积电压在180～190V之间；电泳时间在90S～150S之间。电泳后应先低温烘烤去除水分，然后高温固化；合适的固化温度是170℃左右，合适的固化时间为20Min左右。以此电泳工艺涂层后的粘结NdFeB磁体，涂层厚度在30μm左右，四川大学硕士学位论文放置于T二35℃、5%的NaCI中型盐雾中，间隙式喷雾%H后，磁体的腐蚀增重仅为Zmgo更多还原

【Abstract】 This paper presents comparative systematic research of problems in the preparation of economical mould pressing bonded NdFeB permanent magnets, which include the fabricating of economical rapidly-quenching NdFeB magnetic powder and mould pressing bonded NdFeB permanent magnets; the effect of the NdFeB magnetic powder on the magnetic properties of the magnets and the effect of the cathode electrophoretic coating on the corrosion resistance of the NdFeB magnets.The results shows that the optimum course to produce low cobalt content Nd11(FeCoZr)83B6 powder is: 28m/s quenching, 660℃×40Min crystallization The magnetic properties of the magnets fabricated by the powder are: Br=667.4mT, Hcj=755kA/m, Hcb=443kA/m, (BH)m=75kJ/m3. The ratio of properties to price of the Nd11(FeCoZr)83B6 powder is much higher than that of MQP-B powder.By the compare of seven kinds of hot-curing epoxide resin, we found a kind of mixture cohesion which give attention to both’magnetic properties and compress stress. When compressing, the proper pressure is between 7-11 t/cm2, the keeping time is 60S or so. Mend the method of the compress can improve the density and the magnetic properties of the magnets. The curing of the magnets always in the vacuum circumstance. As far as the mixture cohesion is concerned, the optimized curing temperature and time are 120× and 120Min.Add proper amount of KH550 silane coupling agents and lubricant to the powder can improve the density and the properties of the magnets, the appropriate amount is 1‰-2‰ of the powder, respectively. The granularity arrange can also improve the density and the properties of the magnets. Magnetic select can great improve the properties. Combining press mending with granular arrange and magnetic select, the density and the properties can be improved remarkably.Bonded NdFeB magnets need the protection of the cathode electrophoreticcoating. In order to get proper thickness of the coating, the temperature of the electrophoresis should be controlled between 28℃-30℃; the voltage of the initial stage is 90V, the sediment voltage is between 180-190V; the time of electrophoresis is between 90S-1508. After the electrophoresis, the magnets should be solidified on the low temperature firstly, then solidified in the high temperature. The proper solidified temperature is 170℃, and the time is 20Min. By this course, the magnets will have a coat which thickness is 30um. The magnets will have little increasing weight in the corrosive environment after 96 hours.更多还原