Improved hot workability and magnetic properties in NdFeCoGaB hot deformedmagnets

The hot workability and the magnetic properties of die-upset and backward e xtruded melt-spun magnets with the composition of Nd14.2Fe80.8B5 (MQP-A), a nd Nd13.6Fe73.6 CO6.6Ga0.6B5.6 (MQU-F) have been investigated, Magnets of M QU-F powder show an improved hot workability and better magnetic properties compared to the ternary alloy. Remanence, coercivity and energy product of die-upset MQU-F magnets were found to be B-r = 1.3T, mu ojH(c) = 1.7T, and (BH)(max) = 326 kJm(-3), respectively. SEM and TEM investigations revealed a smaller average grain size in MQU-F magnets, which has a positive effect on the hot workability and magnetic properties. Radially oriented ring mag nets were produced from both alloys and characterized magnetically. The tem perature coefficients of ring magnets were determined to be beta = (dHc/dT) = -0.6%/degreesC and alpha = (dB(r)/dT) = -0.09%/degreesC. A higher deform ation speed can be used for the production of MQU-F magnets, which should m ake the process more economic.