Particulate TiO2 (with varying particle size produced by mechanical milling) dispersed AA7075 composites are synthesised by short duration milling (10 min) followed by room temperature unidirectional compaction (with varying pressure) and sintering. Apparent and relative density of the alloy powder and composites are measured. The effect of reinforcement particle size on the compressibility behaviour of the composites is demonstrated. Mechanically milled (for 25 h) alloy powder shows lower relative density than coarse alloy powder. In addition, compressibility of the alloy composites decreases with decreasing particle size of the reinforcement. In contrast, the sinterability of the composites increases with decreasing dispersoid's size due to easy filling up of finer pores and particle induced precipitation. (C) 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.