摘要 |
A method is disclosed for making a metallic body having desirable magnetic properties. The metallic body is made from an alloy which contains Fe, Cr, and Co and which may also contain one or several additional ferrite forming elements such as, e.g., Zr, Mo, V, Nb, Ta, Ti, Al, Si, or W. According to the disclosed method the alloy is cooled at a rate of at least 60 degrees C. per hour from an initial temperature at which the alloy is in an essentially single phase alpha state to a second temperature which is in a vicinity of 600 degrees C. Subsequently, the alloy is cooled at a second, slower rate to a third temperature which is in the vicinity of 525 degrees C. The disclosed method allows for a relatively broad range of initial temperatures, is relatively insensitive to compositional variations of the alloy, and permits simple reclamation of suboptimally treated parts. As a consequence, the method is particularly suited for large scale industrial production of permanent magnets as may be used, e.g., in relays, ringers, and electro-acoustic transducers. |