Tribological behaviour of cast hypereutectic Al-Si-Cu alloy subjected to sliding wear

Automotive industry is seeking for weight reduction as a consequence to reduce the CO2 emissions to the atmosphere as well as to improve engine performance. Nowadays modern aluminium engine blocks use grey iron for the cylinder bores; however, a new hypereutectic Al alloy was developed to eliminate the grey iron liners from the engine block. The main characteristic that the new alloy has to withstand is the wear resistance. The aim of the present study is to evaluate the wear performance of the new hypereutectic Al-Si-Cu alloy using a pin-on-disk tribometer. For this purpose, samples taken from a V6 aluminium engine block were tested. Metallurgical characterization was assessed using Light Optical and Scanning Electronic Microscopy. The wear evaluation was carried out at different loading conditions (10, 30, 50, 120 N), various sliding speeds (0.5, 1.0, 1.5 m/s), and various sliding distances (5, 10, 20 km), under lubricated and unlubricated conditions. Test was following ASTM G99 standard.