Aging behavior of sub-micron Al2O3P/2024Al composites

Age-hardening behaviors of nearly spherical 0.3 μm-Al2O3 particles reinforced 2024Al composites under the temperature of 160, 175 and 190 °C were studied by means of Brinell-hardness measurement, TEM and DSC. Results show that due to the addition of sub-micro Al2O3 particles, hardness of the composite was obviously improved. While the age-hardening efficiency of Al2O3p/Al composite was lower than that of the monolithic 2024 alloy. Formation of G.P. regions was suppressed and thermal-diffusion activation energy of s′phase was increased which made the precipitation of s′phase more difficult. And the number and size of precipitates in the composite were relatively less and smaller.