Microstructure Evolution in a Fe36Ni36B19.2Si4.8Nb4 Bulk Amorphous Alloy Irradiated by a CO2 Laser Beam
P-L. Zhang, Z-G. Li, C-W. Yao, Z-S. Yu and H. Yan
In this work surface modification of a Fe-based bulk amorphous alloy, Fe36Ni36B19.2Si4.8Nb4, was carried out with a CO2 laser. The as-cast and modified surfaces of amorphous alloys at different conditions were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Crystalline phase such as (Fe,Ni)2B, (Fe,Ni)3B, (Fe,Ni)3Si, γ-(Fe,Ni) and Ni2Si appear at the surface of alloy after laser processing. It was observed that raising laser power can increase the amount of amorphous phases at the surface. It also can increase the surface hardness as it is an effective way to melt alloy completely and reduce the retention time of high temperature at the same time.
Keywords: CO2 laser, alloy, amorphous, surface modification, laser melting, microstructure, amorphous phase, remelting, hardness