|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Hume-Rothery Award Symposium: Alloy Phase Chemistry at the Atomic Level - Opportunities and Challenges
||Design of Nd-Fe-B Permanent Magnets with Maximum Coercivity by Controlling Grain Boundary Chemistry at the Atomic Level
||Kazuhiro Hono, Taisuke T. Sasaki, Hossein Sepehri-Amin, Tadakatsu Ohkubo
|On-Site Speaker (Planned)
Coercivities of permanent magnets are extrinsic properties that are sensitive to microstructures, in particular the grain size and grain boundary chemistry in polycrystalline structures. Magnetic isolation of refined grains is considered to be most effective to maximize the coercivity; however, the commercial sintered magnets have the microstructure far from such an ideal case. In this talk, we will overview the microstructure features of various Nd-Fe-B based magnets based on recent correlative microscopy using SEM, TEM and APT, and point out why the coercivity of Nd-Fe-B magnets are substantially smaller compared to the anisotropy field. By micromagnetic modeling, we show what kind of microstructure and inter-grain exchange will give the maximum coercivity in the Nd-Fe-B system, and finally, present some experimental attempts to optimize the microstructure to maximize the coercivity.
||Planned: Supplemental Proceedings volume