永久磁石材料関連IEC規格の最新動向

摘要

IEC 60404-8-1, Specifications for individual materials—Magnetically hard materials and IEC 60404-5, Permanent magnets (magnetically hard) materials—Methods of measurement of magnetic properties were revised and will be published in September 2015. Processes for revision of these two IEC standards and IEC/TC68 Technical Reports on hard magnetic materials will be presented. The coercivity of Nd-Fe-B sintered magnets applied for HEV, EV and wind turbines is higher than 2 MA/m to keep thermal stability. To measure coercivity higher than 2 MA/m, high magnetic field by open circuit solenoids has been required. Pulsed Field Magnetometry (PFM) and VSM with a high temperature superconductive solenoid have been used for the measurement. Problems and activities related to the IEC standard of the measurement with the open magnetic circuit are also described.