The rare-earth-free hard magnetic material MnBi is potential for permanent magnet high-temperature applications with the ferromagnetic phase formed at low temperature (noted as a Low Temperature Phase – LTP). Up to now, the MnBi powders with high LTP content and coercivity have usually been prepared using the melt-spinning technique. However, the large difference in the melting temperature Tm of the two constituents, Mn and Bi, and the strong reactivity of Bi with the copper-based wheel make the preparation of high-performance MnBi ribbons to be difficult. By using a novel approach which creates buffer layers on the inner wall of quartz tube and the cooper wheel surface, we overcame these difficulties and prepared the MnBi ribbons on the conventional commercial melt-spinning furnace ZGK-1.
5/4/2020 10:35:55 PM +00:00