Structural transformation and property improvement of Fe78Si9B13 amorphous ribbon by pulsed laser processing

The effects of pulsed laser processing (PLP) with different laser power (P-L = 10, 20 and 30 W) on the surface morphology, structure and properties of Fe78Si9B13 amorphous ribbon were investigated. It was found that the circular blobs, convex in perimeter and sunk in middle, distributed regularly on the surface of ribbon after PLP with P-L = 10 W. As P-L increased to 20 and 30 W, obvious splashes occurred around the laser blobs. On the surface of ribbons after PLP, fresh amorphous structures were generated, which were confirmed by small angle X-ray scattering and transmission electron microscope data. Meanwhile, a small number of nanocrystallines formed at heat affected zone. The X-ray diffraction results indicated that the transformation from fcc to bcc SRO structure units occurred during PLP, resulting in a lower characteristic distance delta(C). The pitting resistance, soft magnetic property and thermal stability of ribbons were enhanced after PLP. Especially, the properties had a significant improvement with increasing P-L from 10 to 20 W, but had a slight deterioration as P-L increased further from 20 to 30 W. Overall, an optimal laser power of 20 W was obtained for PLP of Fe78Si9B13 amorphous ribbon in this work. (C) 2018 Elsevier Ltd.