English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Sintered magnets l i ave been produced with powder obtained using the hydrogénation, disproportionation, desorption and recombination (HDDR) process. The HDDR process for the production of the sintered magnets has been adopted in an attempt to reduce the milling time and to investigate its effect on the magnetic properties and microstructure. Commercial cast ingot alloys based on the compositions Pri4Fe75.9COxB6Nbo.i (x = 0; 4; 8; 10; 12; 16) and Pr2o.5Fe72.5B5Cu2.o (sintering aid) have been employed in this investigation. The HDDR powder was used to produce sintered magnets with a mixture of these alloys (alloy main + sintering aid), in the following proportion: 80%wt of the main alloy and 20%wt of the sintering aid. Standard hydrogen decrepitation (HD) magnets have also been included in this work for a comparison (milling time: 20, 15, 10, 5 hours). The sintering temperature and time were kept constant for all magnets (1050°C for 1 hour). The sintered magnet produced using the process HD exhibited the best remanence (1220 mT). It was prepared with the Pri4Fe67.9Co4B6Nbo.i alloy using a milling time of 20 hours. The best intrinsic coercivity was achieved with the Pri4Fe67.9Co4B6Nbo 1 magnet in both processes, namely: 1020 mT for the HDDR process with 5 hours of milling time and 1190 mT for the HD process with 20 hours of milling time. The microstructures of the permanent magnets have been investigated by scanning electron microscopy and energy dispersive X-ray analysis.

Estudo das propriedades magnéticas e da microestrutura em ímãs permanentes à base de Pr-Fe-B-Co-Nb obtidos pelo processo HD e HDDR