Grain boundary optimization induced substantial squareness enhancement and high performance in iron-rich Sm-Co-Fe-Cu-Zr magnets

Increasing iron content has been witnessed an essential method to improve the remanence of 2:17-type Sm-Co-Fe-Cu-Zr magnets, however, the inferior squareness factor accompanied with the increased iron content turns into a neck sticking problem. In this work, the grain boundary optimization induced substantial squareness enhancement from 63.4% to 91.4%, and consequently an excellent maximum energy product of 32.63 MGOe have been achieved in iron-rich Sm-Co-Fe-Cu-Zr magnets via tuning solution process. It is clearly revealed that the grain boundary (GB) phases as well as the micro-twins' density in grain interiors can be controlled and interprets the enhancement mechanism of squareness. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

By optimizing the grain boundary and adjusting the solution process, significant improvement in squareness was achieved in iron-rich Sm-Co-Fe-Cu-Zr magnets, resulting in an excellent maximum energy product. It was revealed that the grain boundary phases and micro-twins' density in grain interiors can be controlled to interpret the enhancement mechanism of squareness.