Detailed studies on the effects of pulsed laser interference heating on surface characteristics and subsurface microstructure of amorphous Fe80Si11B9 alloy are reported. Laser interference heating, with relatively low pulsed laser energy (90 and 120 mJ), but with a variable number (from 50-500) of consecutive laser pulses permitted to get energy accumulation in heated areas. Such treatment allowed to form two- Dimensional micro-islands of laser-affected material periodically distributed in amorphous matrix. The crystallization process of amorphous FeSiB ribbons was studied by means of scanning and transmission electron microscopy. Detailed microstructural examination showed that the use of laser beam, resulted in development of nanostructure in the heated areas of the amorphous ribbon. The generation of nanocrystalline seed islands created by pulsed laser interference was observed. This key result may evidently give new knowledge concerning the differences in microstructure formed during the conventional and lased induced crystallization the amorphous alloys. Further experiments are needed to clarify the effect of pulsed laser interference crystallization on magnetic properties of these alloys.
The effect of laser, as a heat source, on a one-dimensional finite body was studied in this paper. The Cattaneo-Vernotte non-Fourier heat conduction model was used for thermal analysis. The thermal conductivity was assumed temperature-dependent which resulted in a non-linear equation. The obtained equations were solved using the approximate-analytical Adomian Decomposition Method (ADM). It was concluded that the non-linear analysis is important in non-Fourier heat conduction problems. Significant differences were observed between the Fourier and non-Fourier solutions which stresses the importance of non-Fourier solutions in the similar problems.
Paper describes the results of Fe80Si11B9 amorphous ribbon investigation after pulsed laser interference heating and conventional annealing. As a result of interference heating periodically placed laser heated microareas were obtained. Structure characterisation by scanning and transmission electron microscopy showed in case of laser heated samples presence of crystalline nanostructure in amorphous matrix. Microscopy observations showed significant difference in material structure after laser heating – nanograin structure, and material after annealing – dendritic structure. Magnetic force microscopy investigation showed expanded magnetic structure in laser heated microareas, while amorphous matrix did not give magnetic signal. Change of magnetic properties was examined by magnetic hysteresis loop measurement, which showed that the laser heating did not have a significant influence on soft magnetic properties.