Abstract
In this work, the effects of sintering temperature, cooling rate after sintering and post-sintering annealing treatments on the microstructure and magnetic properties of a Nd 11.9MM 2.9Fe 73.9Co 3.3Ni 1.1B 6.9-type magnet have been investigated. It was found that the best magnetic properties were only obtained at a narrow range of sintering temperature at 1333–1353 K. Porosity was found to be minimized with increasing sintering temperature up to 1333 K. However, some grain growth occurred by increasing the sintering temperature from 1333 to 1353 K. Further increase of sintering temperature resulted in a significant decrease in the magnetic properties due to appearance of α-iron in the microstructure of the magnets and/or grain growth. The dependence of intrinsic coercivity ( H cJ) on the cooling rate (after sintering) and post-sintering annealing treatments has been related to electrical conductivity (EC) of the magnets; thus an increase in the EC resulted in a significant improvement in the H cJ values. This could be due to reduction of residual stresses within the specimens during slow cooling after sintering/post-sintering annealing treatments. The compatibility between the variations of the H cJ and EC with the cooling rates (after sintering) or a post-sintering annealing treatment at around 873 K confirms this mater.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
