How are Samarium Cobalt magnets made? Manufacturing process of Samarium Cobalt magnet is starting with the production of an alloy using the vacuum induction melting. The ingots are crushed to about 200 to 400 microns, which are then jet milled to about 2 to 5 microns fine powder. The fine powder is subsequently filled into molds and pressed while a magnetic field applies to orient the individual particles. The compacted green body is densified by sintering using vacuum sintering furnace. For SmCo5 series magnets, green body is sintered at 1150 to 1200 degrees Celsius followed by a heat treatment around 850 degrees Celsius. The magnets are then quenched to obtain acceptable magnetic properties.
For Sm2Co17 series magnets, the sintering process includes three steps: sintering, solid solution, and aging. The green body is typically sintered at 1190 to 1220 degree Celsius followed by a solid solution at 1150 to 1185 degrees Celsius, then quenched to room temperature before a long aging cycle at around 850 degrees Celsius followed by a slow cooling at a rate of 1 degrees Celsius per minute to about 400 degrees Celsius in order to obtain desirable magnetic properties. The blanks are then machined to the specific shapes and magnetized.
