Investigation of the mechanical and tribological effects of al additive on Cu-based spinodal alloys

Nowadays spinodal alloys are used in oil and natural gas systems, aerospace parts that require high strength and wear resistance, thanks to their high conductivity capacities. Today's advancing casting technology and alloy studies reveal the advances in the field of spinodal alloys day by day. It observed that spinodal alloys reach targeted mechanical and chemical values, providing desired properties in many ways, studies and technologies. Spinodal means formation of boundary region between unstable-metastable parts of two-phase region. The resulting microstructure as result of phase system includes phase distributions that homogeneously connected each other. In this thesis, Al element was adjoined Cu15Ni8Sn Ni-bronze copper alloy in a controlled atmosphere. The effects percentage of Al on the microstructure and strength of the alloy were observed. Sn element has been substitute with Al. Al element was added at 2, 4, 6 and 8 wt% instead of Sn. The alloys were melted in graphite melting pot with induction furnace and poured into graphite mold. No heat treatment was applied to casted alloys. The microstructure of the alloys was investigated on Scanning Electron Microscope (SEM) and Optical Microscope (LOM). Mechanical characterizations, hardness measurements and tensile tests performed. Metallographic studies showed that microstructure didn't change with the amount of Al mechanical properties but tribological properties changed. The change of chemical composition in phase was reflected mechanical properties. The composition with the highest hardness and strength among the alloys was found to 4 wt% Al. The alloy with the maximum toughness and ductility belongs Cu15Ni8Al.