1 results about "Gd element" patented technology

This invention provides a core-shell structure R-T-B rare earth permanent magnet with Gd-rich cores for high-temperature environments. In the magnet, the rare earth element R content is 29.0 wt.% to 34.0 wt.%, and R is composed of Gd and R1. The Gd element content is 1.0 wt.% to 20.0 wt.% of the magnet mass. The main phase grains contain main phase grains with a volume ratio of 20 vol.% to 80 vol.% of Gd-rich cores and Gd-poor shells. This invention employs a dual-alloy method to separately melt alloy sheets with high and low Gd contents, then prepares sintered magnets. During high-temperature diffusion treatment, Gd elements in the high-Gd-content main phase diffuse into the R-rich phase at the grain boundaries. Ultimately, the high-Gd-content main phase grains form an anti-shell structure with a Gd-depleted shell and a Gd-rich core. The Gd-depleted shell significantly reduces the degradative effect of Gd on the magnet's coercivity, thus fully utilizing the characteristics of Gd to prepare a magnet with a low temperature coefficient and high coercivity. Grain boundary diffusion treatment of Dy / Tb elements can further improve the magnet's coercivity, preparing R-T-B rare-earth permanent magnets suitable for higher operating temperatures.