Particle Size Refinement and Kinetic Modeling of Hercynite Powders Under Wet Mechanical Milling

Díaz-Tato L.; Iturralde Carrera L.A.; García-Sánchez E.O.; Alvarez Y.C.; Flores-Vivian I.; Ruiz-Valdés J.J.; Rodríguez-Reséndiz J.; Rodríguez-Castellanos E.A. · Journal of Manufacturing and Materials Processing (2026) · DOI: 10.3390/jmmp10070253

Resumen

The particle size refinement of hercynite (FeAl2O4) powders during wet high-energy mechanical milling was investigated through an integrated experimental and kinetic modeling approach. Hercynite powders were milled for different durations, and their microstructural, chemical, and particle size evolution was characterized using scanning electron microscopy, X-ray diffraction, semi-quantitative X-ray fluorescence analysis, and SEM–ImageJ-based particle size reconstruction. Particle size distributions were reconstructed from large particle populations, and the characteristic descriptors (Formula presented.), (Formula presented.), and (Formula presented.) were determined from empirical cumulative distributions. The results revealed a pronounced reduction in median particle size from approximately 83.1 (Formula presented.) m in the as-received powder to 0.422 (Formula presented.) m after 8 h of milling. X-ray diffraction analysis showed progressive peak broadening and intensity reduction with increasing milling time, suggesting milling-induced structural disorder and possible crystallite refinement and/or lattice strain accumulation, while no additional crystalline phases associated with milling-induced decomposition were detected within the detection limit of XRD. Semi-quantitative chemical analysis indicated limited metallic transfer from the stainless-steel milling media under the applied wet milling conditions. The evolution of (Formula presented.) with milling time exhibited a non-linear behavior characterized by rapid particle fragmentation at early stages, followed by a gradual transition toward a refinement-limited regime. This behavior was described using a first-order kinetic model with saturation behavior, yielding an asymptotic particle size of 0.443 (Formula presented.) m and an effective milling rate constant of 1.539 h−1. Overall, the proposed kinetic framework provides a descriptive and condition-specific quantitative basis for interpreting the competing fracture and agglomeration mechanisms governing particle size evolution during wet mechanical milling of refractory spinel powders.

Instituciones: Universidad Tecnológica del Perú