|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials Science for High-Performance Permanent Magnets
||Microstructural Engineering of Nd-Fe-B Permanent Magnets with Significantly Reduced Dy
||Matt Tianen, Catherine Galligan, Jie Li, Peter Moran, Yongmei Jin
|On-Site Speaker (Planned)
Nd-Fe-B magnets with good high temperature coercivity are desirable for applications like traction motors in electric vehicles. Reducing Dy content in these magnets is critical to lowering their cost. Results from our recent proof-of-concept study indicate that Nd-Fe-B with 2.5%Dy exhibits comparable coercivity to commercial magnets containing 7%Dy. This is due to the engineered microstructure where well-aligned submicron grains are magnetically isolated by nonmagnetic intergranular Nd-Cu phase. The magnet was produced by uniaxial hot pressing of Nd-Fe-B and Nd-Cu melt spun ribbons. The Dy content can be further reduced by microstructure optimization. In particular, the grain shape and the thickness of the intergranular phase both impact the coercivity. To quantitatively evaluate the effects of these factors and optimize them, micromagnetic modeling is employed to simulate magnetic domain evolutions in the two-phase Nd-Fe-B/Nd-Cu composite systems under various microstructure conditions. The findings from computer simulations and implications for future experimentation are discussed.