Compression Molding and Novel Sintering Treatments for Alnico Type-8 Permanent Magnets in Near-Final Shape with Preferred Orientation

Journal Article · Fri Jul 14 00:00:00 EDT 2017 · JOM. Journal of the Minerals, Metals & Materials Society

DOI:https://doi.org/10.1007/s11837-017-2453-0· OSTI ID:1374730

Kassen, Aaron G.  ^[1]; White, Emma M. H. ^[2]; Tang, Wei ^[2]; Hu, Liangfa ^[2]; Palasyuk, Andriy ^[2]; Zhou, Lin ^[2]; Anderson, Iver E. ^[1]

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1. Ames Lab. and Iowa State Univ., Ames, IA (United States). Department of Materials Science and Engineering
2. Ames Lab. and Iowa State Univ., Ames, IA (United States)

We present economic uncertainty in the rare earth (RE) permanent magnet marketplace, as well as in an expanding electric drive vehicle market that favors permanent magnet alternating current synchronous drive motors, motivated renewed research in RE-free permanent magnets like “alnico,” an Al-Ni-Co-Fe alloy. Thus, high-pressure, gas-atomized isotropic type-8H pre-alloyed alnico powder was compression molded with a clean burn-out binder to near-final shape and sintered to density >99% of cast alnico 8 (full density of 7.3 g/cm³). To produce aligned sintered alnico magnets for improved energy product and magnetic remanence, uniaxial stress was attempted to promote controlled grain growth, avoiding directional solidification that provides alignment in alnico 9. Lastly, successful development of solid-state powder processing may enable anisotropically aligned alnico magnets with enhanced energy density to be mass-produced.

• Research Organization: Ames Lab., Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: AC02-07CH11358
• OSTI ID: 1374730
• Report Number(s): IS-J-9368; PII: 2453
• Journal Information: JOM. Journal of the Minerals, Metals & Materials Society, Vol. 69, Issue 9; ISSN 1047-4838
• Publisher: Springer
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE