In the present investigation, the Al-18Si-3.6Cu alloy was modified with a 0.36% Ce modifying agent. The modified alloy was (T6) heat treated and aged for 1, 3, 5, and 7 hours at 210 °C. The resulting microstructures were examined qualitatively using optical and scanning electron microscopy (SEM/EDS). The results show that the addition of Ce as a modifier causes a significant change in the morphology of the primary Si from the coarse block with a sharp edge into a spherical form and large-acicular/needlelike eutectic Si into a fibrous and dendritic Al phase into round branches with less interface separation. The microstructure of the modified alloy after ageing for different ageing periods was studied. The study revealed there was no change in the size and morphology of the primary Si phase after heat treatment. However, considerable modification in the eutectic Si phase and the formation of fine precipitates of Al2Cu and Al2CeSi intermetallic compounds in the matrix. A hardness value was found to be significantly high in heat treated alloy, and the 5-hr aged condition alloy depicts high hardness compared to the 1,3 and 7-hr aged conditions. The dry sliding wear behavior of base, modified, and heat treated alloys was investigated by using the Pin on Disc method at different applied loads at 1.0m/s sliding velocity The results indicated that the wear rate for the modified alloy is lower compared to the base alloy. Furthermore, the modified alloy after age hardened treatment imparts high wear resistance and improved wear bearing capacity. The 5hr age hardened alloy exhibited a lower wear rate compared to the base alloy, modified alloy modified and 1, 3,and 7- hr age hardened conditions.
