Abstract
Usually the improved coercivity of rare earth(RE)based 2∶14∶1-type permanent magnets via RE-rich in-tergranular additives is achieved at the cost of more corrosion channels and deteriorated corrosion re-sistance,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)Hx additive.The de-hydrogenated Nd/Pr changes the RE concentration gradients between 2∶14∶1 matrix and intergranular phases during sintering and enlarges the fraction of corrosion-resistant REFe2 phase,rather than the con-ventionally assumed Nd/Pr-rich intergranular phase with high chemical vulnerability.The spontaneous formation of REFe2 intergranular phase after(Nd,Pr)Hx addition generates the uniquely enhanced cor-rosion 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 8.7 to 12.5 kOe with trace addition of(Nd,Pr)Hx.Above findings may spur progress towards developing a high-performance Nd-Ce-Fe-B permanent magnet.
基金项目
国家自然科学基金(52171192)
国家自然科学基金(51801181)
Zhejiang Province Public Welfare Technology Application Research Project(LGG20E010007)
Key Research and Development Program of Zhejiang Province(2020C01008)
Key Research and Development Program of Zhejiang Province(2021C01192)
Key Research and Development Program of Zhejiang Province(2021C01023)
维普
万方数据