Thesis Abstract: Microstructural Characterization of Nanocrystalline Fe-Zr-B(-Cu and/or Ge) Soft Magnetic Alloys

摘要

In the research presented in this thesis, the origins of the microstructure and solute partitioning behaviour are characterized in nanocrystalline Fe-Zr-B(-Cu and/or Ge) alloys in order to design new experimental soft magnetic alloys. The structural and microstructural evolution of nanocrystalline Fe_(93-x-y)Zr_7B_xCu_y alloys (x = 3 and 9 at.%; y = 0 and 1 at.%) was examined, with the aim of investigating the effect of B and Cu additions. The effect of Ge on the microstructural and magnetic properties of Fe_(89-x)Zr_7Bi_3Cu_1Ge_x (x = 0 to 5 at.%) alloys was also examined. The experimental techniques used in this research were differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning transmission electron microscopy (FES-TEM) with nanoprobe energy-dispersive X-ray spectroscopy (NanoEDXS), and dc B-H loop tracer analysis.