Nanocrystallisation of amorphous alloys based on iron

Influence of structure on the evolution of magnetic and mechanical properties of amorphous and nanocrystalline Fe85.4Hf1.4B13.2 alloy

“…Sections of ribbons of 120 mm length were annealed in the temperature range from 373 to 1023 K in vacuum. The annealing time was constant and equal to 1 h, with step of 50 K. The crystallization temperatures (T x1 and T x2 ) of the amorphous alloy were determined from isochronous curve ρ of samples, using the linear heating rate 0.007 K/s with measurement "in situ" [20]. The changes of tapes structures caused by the heat treatment have been investigated by the Xray diffraction method with the use of the filtred Co K␣ radiation.…”

“…This effect, according to the Herzer model [12,17] can be attributed to formation of crystallites with grain size much smaller than the ferromagnetic exchange length, which leads to a random distribution of magnetic anisotropy [13][14][15]. The kinetic of the formation of the nanocrystalline phase depends strongly on the alloy chemistry [20].…”

Microstructure of a Partially Crystallised Ti<SUB>50</SUB>Ni<SUB>25</SUB>Cu<SUB>25</SUB> Melt-Spun Ribbon

“…In fact, up to now, this technique has been used in other fields for casting amorphous alloys with ribbon shapes. 6,7) Production of amorphous material may seem useless in the field of SMA, as it requires a subsequent crystallisation process in order to obtain the martensitic transformation. However, the exceptional ductility of metallic amorphous alloys can be used for shaping the materials, which will exhibit shape memory property after crystallisation.…”

The characterization of structure, thermal stability and magnetic properties of Fe–Co–B–Si–Nb bulk amorphous and nanocrystalline alloys

“…The applied magnetic field had the value of 0.5 A/m and frequency of about 1 kHz. The magnetic after effects ( / ) were determined by measuring the changes of magnetic permeability of the examined alloys as a function of time after demagnetization, where is the difference between magnetic permeability determined at t1 = 30 s and t2 = 1800 after demagnetization and at t1 [11][12][13][14][15][16]. High field magnetization curves were measured by a vibrating sample magnetometer (VSM) in a magnetic field up to 2 T. The magnetizing field was parallel to the sample length to minimize demagnetization effect.…”