Spray forming of the glass former Fe83Zr3.5Nb3.5B9Cu1 alloy

The glass former Fe83Zr3.5Nb3.5B9Cu1 (at.%) alloy was processed by spray forming. The aim was to investigate the possibility of forming novel microstructures using this process. The ratio between the gas mass flow rate and the metal mass flow rate used was 0.23, and nitrogen was used as atomization gas. The resulting deposit, weighting about 0.8 kg, as well as the overspray powder with a median particle diameter about 150 mum, were characterized by using X-ray diffratometry, differential scanning calorimetry and scanning electron microscopy with energy dispersive spectroscopy. Saturation induction (B-s), maximum permeability (mu(max)) and coercive field (H-c) were measured. The overspray powder showed a microstructure consisting of amorphous and alpha-Fe phases. The volume fraction of the amorphous phase decreased as the granulometric size range increased. The deposit presented fully crystalline structure with alpha-Fe, Fe3Nb, Fe2Zr and Fe2B phases. The formation of amorphous phase in the overspray and its absence in the deposit indicates that the deposit was formed by the impacting of a high volume fraction of fully liquid droplets, providing temperature and time enough for complete crystallization of the deposit. (C) 2003 Published by Elsevier B.V.