Usually the improved coercivity of rare earth(RE)based 2:14:1-type permanent magnets via RE-rich intergranular additives is achieved at the cost of more corrosion channels and deteriorated corrosion resistance,which r...Usually the improved coercivity of rare earth(RE)based 2:14:1-type permanent magnets via RE-rich intergranular additives is achieved at the cost of more corrosion channels and deteriorated corrosion resistance,which remains a challenging hurdle in the RE-Fe-B community.Distinctly,here we report the concurrent improvements of corrosion resistance and coercivity in 40 wt.%Ce-substituted Nd-Ce-Fe-B sintered magnets through engineering the intergranular phase using simple(Nd,Pr)H_(x)additive.The dehydrogenated Nd/Pr changes the RE concentration gradients between 2:14:1 matrix and intergranular phases during sintering and enlarges the fraction of corrosion-resistant REFe_(2) phase,rather than the conventionally assumed Nd/Pr-rich intergranular phase with high chemical vulnerability.The spontaneous formation of REFe_(2) intergranular phase after(Nd,Pr)H_(x) addition generates the uniquely enhanced corrosion resistance against the hot/humid and acidic environments,and counts as one peculiar feature of Nd-Ce-Fe-B magnets at high Ce substitution level,being distinct from previously reported Ce-free/lean RE-Fe-B.Simultaneously,the formation of continuous grain boundaries enhances the coercivity from 8.7to 12.5 k Oe with trace addition of(Nd,Pr)H_(x).Above findings may spur progress towards developing a high-performance Nd-Ce-Fe-B permanent magnet.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52171192 and 51801181)the Zhejiang Province Public Welfare Technology Application Research Project(No.LGG20E010007)the Key Research and Development Program of Zhejiang Province(Nos.2020C01008,2021C01192 and 2021C01023)。
文摘Usually the improved coercivity of rare earth(RE)based 2:14:1-type permanent magnets via RE-rich intergranular additives is achieved at the cost of more corrosion channels and deteriorated corrosion resistance,which remains a challenging hurdle in the RE-Fe-B community.Distinctly,here we report the concurrent improvements of corrosion resistance and coercivity in 40 wt.%Ce-substituted Nd-Ce-Fe-B sintered magnets through engineering the intergranular phase using simple(Nd,Pr)H_(x)additive.The dehydrogenated Nd/Pr changes the RE concentration gradients between 2:14:1 matrix and intergranular phases during sintering and enlarges the fraction of corrosion-resistant REFe_(2) phase,rather than the conventionally assumed Nd/Pr-rich intergranular phase with high chemical vulnerability.The spontaneous formation of REFe_(2) intergranular phase after(Nd,Pr)H_(x) addition generates the uniquely enhanced corrosion resistance against the hot/humid and acidic environments,and counts as one peculiar feature of Nd-Ce-Fe-B magnets at high Ce substitution level,being distinct from previously reported Ce-free/lean RE-Fe-B.Simultaneously,the formation of continuous grain boundaries enhances the coercivity from 8.7to 12.5 k Oe with trace addition of(Nd,Pr)H_(x).Above findings may spur progress towards developing a high-performance Nd-Ce-Fe-B permanent magnet.
