Usually it is generally believed that the Er element forms the Er_(2)Fe_(14)B phase,which will seriously deteriorate the magnetic properties.Distinctly,here we report the balance of corrosion resistance and coercivity...Usually it is generally believed that the Er element forms the Er_(2)Fe_(14)B phase,which will seriously deteriorate the magnetic properties.Distinctly,here we report the balance of corrosion resistance and coercivity in Nd-Fe-B sintered magnets through using simple Er_(30)Cu_(70) additive whose price is much lower than Dy and Tb.By reasonably controlling Er_(30)Cu_(70) addition,the corrosion resistance is improved at the minimum limit of reducing the magnetic properties.Through studying the influence mechanism of Er element,it is found that the main effect of Er elements is to replace the Nd elements at the edge of the main phase grains to form a(Er,Nd)_(2)Fe_(14)B shell with low H_(A),resulting in the reduction of magnetic properties.The improvement of corrosion resistance mainly comes from the more stable Cu element introduced at the grain boundary.At the same time,the target magnets also show different advantages under different heat treatment methods.Above findings may spur progress towards developing the lowcost permanent magnets that rival the commercial Nd-Fe-B counterpart.展开更多
基金Project supported by the Natural Science Foundation of Guangxi(2021GXNSFDA075009)the National Natural Science Foundation of China(52261004)。
文摘Usually it is generally believed that the Er element forms the Er_(2)Fe_(14)B phase,which will seriously deteriorate the magnetic properties.Distinctly,here we report the balance of corrosion resistance and coercivity in Nd-Fe-B sintered magnets through using simple Er_(30)Cu_(70) additive whose price is much lower than Dy and Tb.By reasonably controlling Er_(30)Cu_(70) addition,the corrosion resistance is improved at the minimum limit of reducing the magnetic properties.Through studying the influence mechanism of Er element,it is found that the main effect of Er elements is to replace the Nd elements at the edge of the main phase grains to form a(Er,Nd)_(2)Fe_(14)B shell with low H_(A),resulting in the reduction of magnetic properties.The improvement of corrosion resistance mainly comes from the more stable Cu element introduced at the grain boundary.At the same time,the target magnets also show different advantages under different heat treatment methods.Above findings may spur progress towards developing the lowcost permanent magnets that rival the commercial Nd-Fe-B counterpart.
