Influence of sintering temperature on magnetic properties of samarium-cobalt magnets

Sintering of Sm-Co magnets was first reported on in 1969. Because of success in sintering, Sm-Co magnets are now enjoying added importance. Many processing parameters are critical in the preparation of high quality permanent magnets of Sm-Co. One of these is the sintering temperature. Varying the sintering temperature over a narrow range can produce great variations in properties. One particular Sm-Co alloy was chosen for this study. Sintering temperature was varied while all other processing parameters remained constant. Hysteresis measurements were then carried out in a 100 kOe air core magnet using a vibrating sample magnetometer. It was observed that high performance magnets could be obtained only within a narrow range of temperature, with precipitous drops in quality on both sides of the range. Within this narrow range, systematic and significant variations of some intrinsic properties were also observed.