Machining and tolerances
Machining must be performed with a diamond wheel, preferably before magnetization. Standard tolerances are +/-.005” for ground dimensions and +/- 2% of feature size for sintered dimensions. Due to their brittle nature, these magnets will not withstand impact or flexing. They are also not recommended to be used as structural components in assemblies. Ceramic magnets are chemically inert non-conductors, which is a benefit in many applications but eliminates the use of the EDM process to produce samples or special shapes.
Temperature constraints and methods of magnetization
Due to Ceramic’s positive temperature coefficient of Hci high temperatures are not generally a major concern with respect to irreversible magnetic loss. Low temperatures, however, pose a much greater risk for permanent demagnetization. For example, a ceramic 5 grade with a permeance coefficient of 1 will start to experience permanent losses below -20°C.
Isotropic ceramic grades can be magnetized in any direction, while anisotropic grades have a preferred direction of magnetization and will only meet their full magnetic potential when magnetized along the “easy axis.”
Gauss Calculations of Ceramic Magnets
Adams will help you calculate magnetic field strength measured in Gauss, on the centerline of a disc magnet or ring magnet magnetized through its thickness, at a distance of X from the surface of the magnet. To get started, please click here.
Adams’ Elmhurst facility is ISO9001:2008 certified, and DFARS and ITAR compliant.