Microstructure analysis of Ti-doped sintered Nd-Fe-B magnets
Source abstract
Abstract
A systematic microstructure analysis has been carried out for the as-sintered and annealed Ti-doped sintered Nd-Fe-B magnets. Upon annealing, grain boundaries become more obvious and show higher Nd content and lower Fe content, leading to the improvement of coercivity. Meanwhile, the amount of Nd 6Fe 13Ga increases and that of Nd 2Fe 14B decreases, leading to a slight loss of remanence. Many rod-shaped TiB 2 precipitates are found both in the as-sintered and annealed samples with most of them located at grain boundaries. There is no significant difference between the as-sintered and annealed sample in the distribution, grain shape and size of TiB 2. Atomic-scale characterization of TiB 2 and its neighboring area reveals the existence of an amorphous layer surrounding TiB 2 with the thickness of 3.5 ± 2.5 nm. The amorphous layer is measured and analyzed to be non-ferromagnetic with obvious enrichment of Nd and Pr. Its existence is speculated to be the result of strong cohesion of Ti and B, leaving a B-poor region around TiB 2 difficult to form stable crystals. The existence of TiB 2 and the surrounding (Nd,Pr)-rich amorphous layer in the Ti-doped magnets is beneficial for preventing the propagation of reversed magnetic domains and improving coercivity.
Source: expertdata · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Magnetic Properties of Alloys · Magnetic Properties and Applications · Magnetic properties of thin films
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
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