Abstract
Rapidly quenched Nd‐Fe‐B magnets show a pronounced composition dependence of the intrinsic coercivity HcI which increases with increasing Nd content to values of 23.5 kOe. The magnetic hardening is ascribed to a Nd‐rich phase located at the phase boundaries of the Nd2Fe14B grains. Samples prepared by crystallization of amorphous ribbons have slightly lower coercivities but are less sensitive to prolonged heat treatment at higher temperatures. The microstructure obviously differs for the two types of material.