Enhanced Magnetic Properties of Sintered Ce–Fe–B-Based Magnets by Optimizing the Microstructure of Strip-Casting Alloys

Abstract

We present an effort to enhance the magnetic properties of sintered Ce-Fe-B-based magnets by optimizing the microstructure of strip-casting (SC) alloys. The results indicated the microstructure in the Ce <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">30.5</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">bal.</sub> B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> SC alloy was characteristic for peritectic solidification and Ce <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">14</sub> B coexisted with CeFe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and primary Fe-rich phase. After alloying a little amount of Ho and Nd, the microstructure of Ce-Fe-B strip was optimized toward that of Nd-Fe-B strip. Experimental results indicated that all magnetic properties, especially the energy product, were enhanced after optimizing the microstructure of SC alloy. Fracture surface images of the magnets illustrated the grain boundary structure was also modified due to optimization of the microstructure of SC alloys.