ECAP consolidation of Al matrix composites reinforced with in-situ γ-Al2O3 nanoparticles

This work is aimed at proposing a method to prepare aluminum matrix composites reinforced with gamma-Al2O3 nanoparticles and at describing the effects of an in-situ reaction on the resulting nano-reinforcement dispersed throughout the metal matrix. Al nano- and micro-particles were used as starting materials. They were consolidated by equal channel angular pressing (ECAP) in as-received conditions and after undergoing high-energy ball milling. Further, gamma-Al2O3 reinforcing nanoparticles were produced in-situ from the hydroxide layer that covered the Al powder particles. The powder particle morphology and the composites microstructures were investigated by electron microscopy. The transformation process was monitored by X-ray diffraction, differential scanning calorimetry and thermo-gravimetric analysis. (C) 2015 Elsevier B.V. All rights reserved.