Hot isostatically pressed Sm(2)(TM)17 magnets

High energy product TDK-type, 2-17,Sm (Cu, Fe, Zr, Co) z magnets were produced successfully using hot isostatic pressing (HIP). The best combination of properties was obtained in magnets containing about 26.5 wt% Samarium, 4 wt% Copper, 20 wt% Iron, 2 wt% Zirconium, and 0.4 wt% Oxygen, and balance cobalt. The maximum value of (BH) max measured was 24.8 MGOe for a magnet with B sub R = 10.7 kG and H sub ci = 15.5 kOe. With higher levels of Cu (up to 8 wt%) much higher H sub ci values (up to 28.5 kOe) were measured. A minimum amount of Zr was found to be essential to H sub ci development. HIPing was successfully performed at 1100 C. This resulted in near-complete densification with little grain growth. Post-HIP homogenization was found to lead to enhanced properties after solution treatment and aging, 825 C was determined as the optimum peak aging temperature. Magnets produced from coarse (15 min grind time) alloy powders (with low oxygen contamination) had the properties indicated above. These were substantially superior to magnets produced from conventionally made much finer (1 hour grind time) sinter grade powder, which contained a higher level of oxygen and showed lower H sub ci even after excess Sm was added to compensate for the higher oxygen. However, H sub ci values of up to 8 kOe were found to develop in magnets made from fine (1 hour grind time) powders which were processed for lower oxygen contamination in a glove box.