Effect of different zinc contents on the structural, mechanical and tribological properties of EN AC-48100 (Al-17Si-4Cu-Mg) Alloy

Abstract

In this study, Al-17Si-4Cu-0.6Mg-0.2Ti which is based of the EN AC-48100 alloy, Al-17Si-4Cu-0.6Mg0.2Ti-1Zn, Al-17Si-4Cu-0.6Mg-0.2Ti-2Zn, Al- 17Si-4Cu-0.6Mg-0.2Ti-3Zn, Al-17Si-4Cu-0.6Mg-0.2Ti-4Zn and Al-17Si-4Cu-0.6Mg-0.2Ti-5Zn alloys were produced by permanent mold casting method. Chemical composition of the produced alloys was determined by the spark optical emission spectrometer method. the microstructures of the alloys were examined by optical and scanning electron microscopy. the hardness and microhardness of the alloys were determined by Brinell and Vickers measurement methods, respectively, and their mechanical properties were determined by tensile tests performed by a universal test machine. It was observed that the microstructure of the Al-17Si-4Cu-0.6Mg-0.2Ti-(0-5) Zn alloys consisted of aluminum-rich alpha, eutectic Al-Si, primary silicon, copper-rich theta (CuAl2), Mg2Si and pi phases. It was also observed that zinc additions did not lead to a new phase formation in the Al-17Si-4Cu-0.6Mg-0.2Ti alloy. the hardness of the produced alloys increased with increasing zinc content, but yield and tensile strength and wear resistance increased up to 3% zinc content and decreased after this ratio. Smearing layers, fine scratches and peeling occurred are seen on the surfaces of the wear samples. the morphology of the wear particles collected after wear tests did not show significant change with the zinc content. the results obtained from the mechanical and tribological tests of the produced alloys were discussed in terms of the microstructural features of the alloys.