Tensile behaviour of powder metallurgy processed (Al-Cu-Mg)/SiCp composites

The tensile behaviour of Al-Cu-Mg alloy matrix composites produced by a pow der metallurgy process was investigated as a function of particle size in t he as extruded, homogenised, and peak aged conditions. The tensile behaviou r of the corresponding matrix alloy which was produced in a similar manner, designated as Control, was also studied. There was a significant increase in the 0.2% yield strength of Control and all the metal matrix composites ( MMCs) after homogenisation treatment (53-68%) and peak aging (93-109%), as compared to their values in the as extruded condition. The ultimate tensile strength (UTS) of Control as well as the MMCs also increases considerably after homogenisation treatment (39-70%), however, subsequent peak aging did not result in any further increase in UTS in case of any of the MMCs. It w as found that the finer the reinforcement size, the higher the 0.2% yield s trength and UTS in all the conditions. On the other hand, ductility decreas ed considerably after homogenisation treatment and subsequent peak aging. T he results are discussed in the light of dislocation strengthening as well as reinforcement damage. MST/4438.