Manufacturing Methods for Samarium Cobalt Magnets

Processes and techniques were established for the pilot line manufacturing of samarium-cobalt permanent magnets for use in high performance periodic permanent magnet focused traveling-wave tube amplifiers. The objective of achieving a capacity for 1000 magnets per month was exceeded. Typical properties of magnets produced in quantity are: energy product (BH max of 13 - 15 x 1,000,000 GOe, B sub r of 7800 plus or minus 200 gauss, and Hc of 6800 plus or minus 300 Oe. Extensive measurements were made to establish temperature characteristics of second quadrant properties, long term stability, and maximum temperature use in an operating device. Irreversible temperature coefficients for magnetic properties up to 255C were found to depend linearly on demagnetizing field, whereas reversible temperature coefficients varied only slightly. Magnet rings assembled in a PPM stack (high demagnetizing factor) exhibited