Thermally induced crystallization of amorphous Fe40Ni40P14B6 alloy

Thermal Stability and Phase Transformations of Multicomponent Iron-Based Amorphous Alloys

“…Application of TEM method confirms the results of XRD analysis and Mössbauer spectroscopy in terms of crystalline phases formed during heating [18,20], showing that, after heating at the highest temperatures, the alloy structure is composed of grains, several 10s to several 100s of nanometers in size and irregular in shape, which are formed by coalescence of neighboring grains and influenced by impingement (Figure 4) [19][20][21]. Crystallization changes the morphology of the alloy sample and the distribution of individual elements on the surface of a sample [19,20], which, after formation of crystalline phases, becomes nonuniform. As a result of crystallization, the alloy structure is more porous, because of imperfect packing of the crystals (Figure 4b) [17,20,26].…”

“…Iron-based amorphous alloys studied herein were prepared in the form of the 30-35 μm thin ribbons by melt-quenching technique [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. The nominal composition of the as-prepared alloy samples can be represented as follows in atomic %: Fe 81 Si 4 X-ray diffraction (XRD) measurements were performed in Bragg-Brentano geometry, using a Co K α radiation source, at room temperature.…”

“…Thermal analyses of the studied alloys were carried out by means of differential scanning calorimetry (DSC) in a protective nitrogen or helium atmosphere, at constant heating rates. Complex crystallization peaks were deconvoluted [19,[21][22][23][24] Thermal Stability and Phase Transformations of Multicomponent Iron-Based Amorphous Alloys DOI: http://dx.doi.org /10.5772/intechopen.88260 using either Gaussian-Lorentzian cross-product function or Fraser-Suzuki function, taking into consideration the criteria related to the nature of the process as well as the mathematical criteria.…”

“…The peak shape of exothermal stabilization maxima, sharp or rounded in some degree, and the presence of more than one maximum (Figure 2) indicate the occurrence of several parallel or consecutive steps of thermal stabilization, for all the studied alloys [19,[21][22][23][24] (Figure 2a), which correspond to different crystallization and recrystallization steps. The alloy containing equal amounts of Fe and Ni (40% at.)…”

“…As a result of crystallization, the alloy structure is more porous, because of imperfect packing of the crystals (Figure 4b) [17,20,26]. Surface morphology depends significantly on the heating rate and the temperature up to which the sample was heated, in other words on thermal history of a sample [19].…”