Materials Science and Engineering A 375–377 (2004) 571–576 Spray forming of the glass former Fe 83 Zr 3.5 Nb 3.5 B 9 Cu 1 alloy C.R.M. Afonso ∗ , C. Bolfarini, W.J. Botta Filho, C.S. Kiminami Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Caixa Postal 676, São Carlos 13.565-905, SP, Brazil Abstract The glass former Fe 83 Zr 3.5 Nb 3.5 B 9 Cu 1 (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 diam- eter about 150 m, were characterized by using X-ray diffratometry, differential scanning calorimetry and scanning electron microscopy with energy dispersive spectroscopy. Saturation induction (B s ), maximum permeability (μ máx ) and coercive field (H c ) were measured. The overspray powder showed a microstructure consisting of amorphous and -Fe phases. The volume fraction of the amorphous phase de- creased as the granulometric size range increased. The deposit presented fully crystalline structure with -Fe, Fe 3 Nb, Fe 2 Zr and Fe 2 B 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. © 2003 Published by Elsevier B.V. Keywords: Spray forming; Fe-based alloy; Magnetic properties; Characterization 1. Introduction Spray deposition, also called spray casting or spray form- ing, involves the inert gas atomization of a liquid metal stream into variously sized droplets which are then propelled away from the region of atomization by the fast flowing, atomizing gas. The droplet trajectories are interrupted by a substrate which collects and solidifies the droplets into a co- herent, near fully dense deposit. By continuous movement of the substrate relative to the atomizer as deposition proceeds, large deposits can be produced in a variety of geometries including deposits, tubes and strips [1]. As-spray formed deposits always contain some porosity and are usually con- solidated to full density by extrusion, hot/cold rolling or hot isostatic pressing. The powder which was not incorporated in the deposit and was collected in the bottom of the atom- ization chamber is called overspray powder and is usually in the range of 20% in weight of the starting charge [1]. Nanocrystalline Fe–M–B–Cu alloys (M = transition metal) have attracted great attention due to the fact that they show excellent soft magnetic properties. In particular, ∗ Corresponding author. E-mail address: perma@iris.ufscar.br (C.R.M. Afonso). in the partially crystallized state known as “nanocrystalline alloys”, their amorphous matrix contains -Fe nanocrystals that exhibit high effective permeability and low coercive force, plus a high saturation magnetic flux density [2–4]. These magnetic properties make these alloys promising candidates for several practical applications as in magnetic parts of powers transformers, data communication inter- face components, electro-magnetic interference prevention components, magnetic heads, sensors, magnetic shielding and reactors [5–10]. Makino et al. [5] reported the devel- opment of a new alloy, Fe 83 Nb 3.5 Zr 3.5 B 9 Cu 1 (at.%), the melt-spinning process with ribbons 20–30 m thick in the nanocrystalline state (with the -Fe around 10 nm, em- bedded in an amorphous matrix) that presented saturation induction, B s = 1.5 to 1.6T, coercive force, H c = 1 to 2 A/m, relative permeability, μ r = 10 × 10 4 to 12 × 10 4 at frequency of 1 kHz and saturation magnetostriction, λ s close to zero. Our group has been working with the spray forming of a variety of materials; for example: Cu–Zn [11], Zn–Al–Cu [12], high chromium white cast iron [13] and Fe–Si alloys, with good commercial magnetic applications [14]. The ob- jective of this work is to investigate the microstructures of the spray formed Fe 83 Nb 3.5 Zr 3.5 B 9 Cu 1 (at.%) alloy and its applicability as a soft magnetic material. 0921-5093/$ – see front matter © 2003 Published by Elsevier B.V. doi:10.1016/j.msea.2003.10.012