Processing for thin strip Fe-Cr-Co magnet alloys

A new processing scheme suitable for commercial production has been developed so that the Fe-28Cr-10.5Co magnet alloy can be used as a replacement for high cobalt Vicalloy (52Co-38Fe-10V) in thin strip (1-2mil) permanent magnet applications, offering the advantages of lower cost, lower cobalt content, improved rust resistance, and easier processing. However, since the aging heat treatment necessary to achieve magnetic properties of Br9.8- 10.8K Gauss and Hc220-380 Oe requires several hours for the Fe-Cr-Co alloy, conventional strand annealing facilities cannot be used. It has been shown that the Fe-Cr-Co alloy can be processed into thin strip form using a new processing sequence of annealing, cold rolling to size, coiling, aging and a finishing 'skin pass' or reverse coiling to remove coil set, the processing scheme being suitable for commercial manufacture of the alloy.