Effect of mechanical milling on powder characteristics of Fe-based metal matrix composites reinforced with WC-Co and NbC particles

In this work we analyze the particle size distribution (PSD) and phase characteristics of three different metal matrix composites (MMC) produced by mechanical milling. Three mixtures containing a Fe-based matrix and reinforcements of WC-Co and NbC particles were milled for periods of 1 and 24 h. The mixing/milling process was done by conventional ball milling. The efficiency degree of the milling process was analyzed by the parameters D10, D50 and D90 associated with each PSD. Alloying effect of the milling treatment was analyzed by X-ray diffraction. Different powder characteristics were obtained by controlling the hard phase reinforcement and the milling time. The particle-size distribution curves indicate that short milling times are suitable for MMC reinforced with WC-Co particles with potential use in weld deposition techniques, whereas the MMC reinforced with NbC particles (milled for 24 h) would have a potential application in thermal spray coating techniques. X-ray diffraction studies revealed that no mechanical alloying is induced under the conditions investigated.