Effect of volume fraction and particle size of alumina reinforcement on compaction and densification behavior of Al–Al2O3 nanocomposites

Al–Al2O3 nanostructured composite powders containing 1, 3 and 7 percent volume fraction (vf%) of submicron/nanometeric alumina particles as reinforcement phase were produced by high energy milling. The powders were consolidated by a uniaxial cold press and sintered for various durations of time. Effects of reinforcement particle size and volume fraction on compaction and sintering behavior of nanocomposite powders were investigated considering relative density as the main criterion. It was found that the nanometeric alumina particles had a more hindering effect on densification of the composite powders as compared to the submicron particles. The hindering effect was found to be aggravated by higher volume fractions of the reinforcement particles.