R-TM-B SERIES PERMANENT MAGNET HAVING IMPROVED CORROSION RESISTANCE AND FILM THICKNESS UNIFORMITY

摘要

PURPOSE:To remarkably improve corrosion resistance and film thickness uniformity insufficient in conventional plating in a magnet containing rare earth elements and iron as main ingredients. CONSTITUTION:An R-TM-B series permanent magnet having improved corrosion resistance and film thickness uniformity comprises double layers formed of an electrolytic Ni-strike-plated layer and an electroless Ni-P-plated layer formed thereon on the surface of the R-TM-B series permanent magnet containing by weight 5-40% of R (R is a combination of one or more types of rare earth elements including Y), 50-90% of TM (TM is transition metal containing Fe as a main ingredient) and 0.2-8% of B (boron).