Influence of ball milling parameters on microstructure and magnetic properties of aluminum bronze chips reinforced with vanadium carbide

This article analyzes the influence of mechanical ball milling parameters on processed aluminum bronze chips in order to increase the efficiency of this process in terms of particles' size reduction. Also evaluated is the addition of vanadium carbide (VC) in this response, along with its microstructure and magnetic properties. The experiments have been carried out in accordance with DOE design methodology. After machined, its residues can still be reused to produce composites through powder metallurgy routes, preserving good mechanical properties without onus to the environment. The study aims to produce and characterize powders resulting from ball milling processes, identifying the influential parameters, in addition to verify its soft magnetization behavior. The powder morphologies and particle sizes underwent scanning electron microscopy (SEM), coupled with energy-dispersive spectroscopy (EDS) and laser diffraction particle analyses, respectively, in addition to phase identification via X-ray diffraction (XRD). Moreover, saturation magnetization (Ms), remanent magnetization (Mr), coercivity (Hc), and remanence-to-saturation ratio (Mr/Ms) were determined through magnetic hysteresis curves obtained from a vibrating sample magnetometer (VSM). Results indicate that % VC and milling time are the main parameters to improve the milling efficiency and obtain submicrometric particles with sizes almost 800 times smaller than the initial chips. After the milling process, aluminum bronze powders presented certain amorphization, a decrease of about 24% in Ms and an elevation about 81% in Hc, both compared with the as cast material. The Mr/Ms ratio indicates a slight conservation of magnetization.