Effect of Annealing on Magnetic and Mechanical Behaviors of NANOPERM-Type Alloys

Microstructure, ac magnetic, and mechanical properties of the Fe
₇₆
Mo
₈
Cu
₁
B
₁₅
alloy in the amorphous and nanocrystalline state were studied. Transmission electron microscopy was used to analyze the amorphous structure of as-quenched precursor and nanocrystalline phase of sample annealed at 783 K for 1800 s, i.e., the above primary crystallization temperature. Creation of α-Fe nanograins with an average grain size of 8.6 nm affects magnetic and mechanical properties. In order to understand the correlation between structural changes resulting in soft magnetic properties in the Fe
₇₆
Mo
₈
Cu
₁
B
₁₅
alloy frequency characteristics of complex permeability and core loss were drawn in the wide range of frequency and magnetic field. Moreover, from dependence of core losses versus maximum magnetic induction Steinmetz coefficients were also calculated for the as-quenched and annealed Fe
₇₆
Mo
₈
Cu
₁
B
₁₅
alloy. Nanoindentation tests with Berkovich diamond indenter were performed for amorphous and nanocrystalline samples for analysis mechanical properties of pure amorphous matrix and nanocrystalline structure represented by α-Fe grains embedded in amorphous residue.