Journal Article

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

Palasyuk, Andriy, Tang, Wei, Zhou, Lin, Hu, Liangfa, Kassen, Aaron G., White, Emma M. H., Anderson, Iver E.

2017

Overview

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/cm 3 ). 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. Successful development of solid-state powder processing may enable anisotropically aligned alnico magnets with enhanced energy density to be mass-produced.

• Publisher: Springer US,Springer Nature B.V,Springer
• Subject: Alignment / Alloy powders / Alloys / Atomizing / Chemistry/Food Science / Cobalt base alloys / Decomposition / Directional solidification / Earth Sciences / Energy / Engineering / Environment / Ferrous alloys / Flux density / Grain boundaries / Grain growth / Grain size / Laboratories / Magnetic fields / Magnetism / MATERIALS SCIENCE / Microstructure / Motors / Nickel base alloys / Permanent magnets / Physics / Preferred orientation / Pressure molding / Rare earth elements / Remanence / Sintering / Solids / Studies / Temperature