The high-performance permanentmagnets are constituents of wind turbines, electric cars and vehicles etc. The anisotropic nanocomposite magnets – magnets with a mixture of nanostructured hard and soft ferromagnetic phases – will be a new type of permanent magnets . Avariousmethodsaredevelopedforproduction nanocomposites. A combination of high energy ball milling, an electroless coating, and hydrogen treatment, as sintering method, have a big perspective for obtaining nanocomposites.
The phases content, powder morphology and sintered alloy microstructure of Sm2(Co,Fe,Zr,Cu)17/Fe-based ferromagnetic composites were investigated by scanning electron microscopy (EVO-40XVP), X-ray energy dispersive spectrometry (INCA Energy 350) and X-ray phase (DRON-2.0М, Fe Кα radiation) analysis. An as-cast alloy was milled in a planetary mill under hydrogen. The powder particles then coated with Fe using iron sulfate (FeSO4٠7H2O) as metal precursors. The composite particles were pressed and sintered under vacuum and hydrogen at temperatures up to 950 °C. Two types of powders were investigated: milled and disproportionated one after milling.
The FeCo phase has homogeneous distribution it was revealed after sintering of Sm2(Co,Fe,Zr,Cu)17/Fe-based ferromagnetic composite. The FeCo phase has grain size in the range of 200 – 650 nm.
Kneller E. F., Hawig R. The Exchange-Spring Magnet: A New material principle for permanent magnets. IEEE Trans. Magn.-1991.-27.-P. 3588–3600.