Emma M. White PhD, Associate Scientist, Ames Laboratory of USDOE
Alternatives to rare earth magnets, such as alnico, will eliminate supply instability and decrease costs of permanent magnets for applications such as traction drive motors. Processing of alnico magnets with a higher energy product involves directionally solidified casting and final machining which increases costs and material waste. Additive Manufacturing (AM) is an effective method to build net-shape parts with excellent material properties, and AM has great potential to be applied in the permanent magnet industry. This presentation describes enhanced alnico magnets produced by AM using a laser engineered net shaping (LENS) system. Modified alnico-“8” compositions were high-pressure gas atomized into high purity, spherical powder with low oxygen content. Cylinders were built out of these powders, heat treated, and characterized for microstructure and magnetic properties. The resulting alnico magnets have been characterized using SEM, EBSD, and hysteresigraph measurements. The improved properties demonstrate the promise for “printing” alnico magnets into net-shapes for use in next generation motors and other applications requiring complex engineered part geometries. Work funded by USDOE-EERE-VT-EDT program through Ames Lab contract no. DE-AC02-07CH11358.