|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials Science for High-Performance Permanent Magnets
||Reduced Cobalt Energy Efficient “Green” Alnico
||Andriy Palasyuk, Brandon Kiel, Kevin Dennis, Wei Tang, Lin Zhou, Aaron Kassen, Emma White, Mathew Kramer, Iver Anderson
|On-Site Speaker (Planned)
The novel alloying concept of equi-electronic replacement of the critical element Co by more abundant Fe and Ni showed that the unique self-assembled spinodal nanostructure of alnico remains unchanged even when the total Co content is reduced by 45%. According to the Rigid Band Approximation this is due to minimal disruption in total electron concentration of the system, i.e. e/a ≈ constant, maintaining the electronic structure even after significant chemical modification. Application of equi-electronic Co-reduction saves not only critical material but significantly lowers the solution annealing temperature and other processing parameters, while preserving and/or significantly improving performance of alnico 8, e.g., magnetic coercivity. Depending on the amount of Co that is being reduced, the coercivity varies from ~1500Oe in magnets with 40-45% less Co to ~2500Oe in alloys with 15-20% of Co reduction. Supported by USDOE-EERE-VT-EDT, within the DREaM project at Ames Laboratory, operated by ISU under contract no. DE-AC02-07CH11358.