Abstract <p>Al–4.5 wt % Cu alloy powder was ball milled for 15 h to reduce the size of the powder. The ball milled powder was compacted for different temperatures of 400, 450 and 500°C at a constant pressure of 30&#xa0;MPa using spark plasma sintering technique. The displacement and densifications curves were studied for different sintering temperatures to investigate the mechanisms involved during the spark plasma sintering process. The temperature effect on microstructure or surface topography and mechanical properties of sintered compacts were studied. The surface topography of the sample sintered at 400°C revealed that the compact is not densified sufficiently. The density of the compacts are increased from 2.77 to 2.83 g/cc as the sintering temperature was increased from 400 to 500°C. The scanning electron micrographs exhibit the distribution of Al₂Cu phase within the grains. The transmission electron micrographs showed the presence of nanosized Al₂Cu precipitates in the sintered compact. The micro Vickers hardness of the sintered compacts is 142 ± 2.40, 204 ± 2.80 and 171 ± 2.7 HV. There is a significant increase in hardness as the temperature is increased from 400 to 450°C and the hardness is decreased as the sintering temperature is increased from 450 to 500°C due to softening of the compact at higher temperature. The compacts sintered at 450 and 500°C showed the highest compressive strength than the compact sintered at 400°C. The nano-structured Al₂Cu precipitates, uniform distribution of precipitates and the precipitation strengthening are found to be the dominating mechanism.</p>