Thin laminates made of soft magnetic alloys
Numerous pieces of electro-technical equipment include magnetic parts made of soft magnetic alloys. In particular, iron-cobalt intermetallic alloys have the unique combination of high saturation magnetisation, high Curie temperature and low magnetocrystalline anisotropy. Intense research and development efforts over the years achieved a better understanding of phase transitions and significant improvements in mechanical properties of iron-cobalt alloys. Their high cost has, however, prevented their widespread application. Emerging needs for soft magnetic materials inspired the project FECOPROGEN (FeCo based magnetic alloys with high strength and minimized iron losses, for new high speed aerospace generator). Its aim was to develop an original metallurgical path for equiatomic iron-cobalt alloys. Researchers started with usual AFK502R-grade manufactured by Aperam Alloys Imphy that essentially contains about 49 % cobalt, 2 % vanadium and less than 0.04 % niobium. The remainder consists of iron and small amounts of impurities resulting from the elaboration of the material in bands. Through careful elaboration of key processing parameters, including annealing speed and temperature as well as the cold rolling ratio, researchers produced two-stage laminates with 0.2-mm thickness. The new grade is easy to stamp and cut in pieces using industrial tools. FECOPROGEN work resulted in a new iron-cobalt laminate that will allow manufacturers of aerogenerators to develop lighter devices delivering the same power. The new product combining exceptional mechanical and magnetic properties is expected to increase Europe's share in the world market of iron-cobalt laminates.
Keywords
Laminates, magnetic alloys, iron-cobalt alloys, FECOPROGEN, aerogenerators