JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI, cilt.19, ss.585-592, 2016 (ESCI İndekslerine Giren Dergi)
In this study, A356 alloys with various amount of Cu (0.1-0.4 wt. %) were produced by casting and the effects of Cu content on the microstructure and wear behaviour of these alloys were investigated. T6 heat treatment was applied to the produced A356 alloys. The microstructures of the produced A356 alloys were examined by optical microscope (OM), scanning electron microscopy (SEM), X-Ray diffraction analysis (XRD) and hardness measurements. Wear tests were carried out on a pin-on disk type wear apparatus at 1 ms(-1) sliding speed for different sliding distances (500, 1000, 1500 and 2000 m) under different loads (10, 20 and 30 N). The results showed that the morphology of Al-Si eutectic was refined and distributed uniformly in the microstructure with increasing Cu amount. In addition, iron-based intermetallic phases formed in the microstructure were also seen to be refined. With increasing Cu amount added to A356, the amount of Al2Cu precipitates (due to aging) and the hardness values of the alloys increased. According to the wear test results, while the lowest wear rates were obtained for A356 alloys with 0.2% and 0.4% Cu under 10 and 20 N loads, the lowest wear rate under 40 N load was obtained for A356 alloy with 0.4% Cu content.