AlCuFe纳米颗粒对钕铁硼磁性及抗腐蚀性的影响

Effect of AlCuFe nanoparticles on magnetic properties and corrosion resistance of NdFeB

为了提升烧结NdFeB的磁性能和耐腐蚀性,采用晶界掺杂Al_(65)Cu_(20)Fe_(15)纳米颗粒方法制备了高性能烧结NdFeB磁体,利用电化学工作站研究了掺杂磁体在3.5%NaCl溶液中的腐蚀行为。结果表明:Al_(65)Cu_(20)Fe_(15)纳米颗粒的掺杂可在磁体中形成低熔点相,提高晶界与主相的润湿性,抑制硬磁相之间的磁耦合,增强磁体的磁性能。当Al_(65)Cu_(20)Fe_(15)纳米颗粒的质量分数为0.4%时,磁体的磁性最大,矫顽力为978.1 kA/m,最大磁能积为270.3 kJ/m^(3),剩磁为1.208 T。与未掺杂磁体相比,掺杂0.4%Al_(65)Cu_(20)Fe_(15)纳米颗粒后磁体的腐蚀电位从-0.8816 V增至-0.7040 V,腐蚀电流密度从78.2929μA/cm^(2)减至33.2229μA/cm^(2),且高频容抗弧半径远大于未掺杂磁体,因而磁体的耐腐蚀性得到有效提升。

In order to improve the magnetic properties and corrosion resistance of sintered NdFeB,grain boundary doped Al_(65)Cu_(20)Fe_(15) nanoparticles were used to prepare sintered NdFeB magnets with high performances,and an electrochemical workstation was used to investigate the corrosion behaviour of doped magnets in 3.5%NaCl solution.The results show that the doping of Al_(65)Cu_(20)Fe_(15) nanoparticles can form a low melting point phase in the magnet,improve the wettability between the grain boundary and the main phase,inhibit the magnetic coupling among the hard magnetic phase,and enhance the magnetic properties of the magnets.When the mass fraction of Al_(65)Cu_(20)Fe_(15) nanoparticles is 0.4%,the magnet has the highest magnetic force with the coercivity of 978.1 kA/m,the maximum magnetic energy product of 270.3 kJ/m^(3) and the remanence of 1.208 T.Compared with the undoped magnet,the corrosion potential of magnet doped with 0.4% Al_(65)Cu_(20)Fe_(15) nanoparticles increases from-0.881 6 V to-0.704 0 V,while the corrosion current density decreases from 78.292 9 μA/cm^(2) to 33.222 9 μA/cm^(2),and the arc radius of high frequency capacitive reactance is much larger than that of the undoped magnet.Therefore,the corrosion resistance of the magnet can be effectively improved.