Machinability characteristics in Zn-40Al alloy: The effect of addition of copper and silicon and optimization of cutting parameters using response surface methodology

In this study, the impacts of Cu and Si additions to Zn-40Al alloy on its microstructural, mechanical and machinability properties were investigated in the turning process. Zn-40Al and alloys containing 2 % Cu and 2 % Si were obtained by PMC. OM and SEM examinations and standard mechanical tests qualified the samples obtained from the mould. Produced alloys were subjected to machinability tests at different V , f and constant DoC parameters using a PVD-ZrN+TiAlN coated insert. CNC lathe was used to determine F , Ra and tool wear in machinability tests. While the microstructure of Zn-40Al comprised of alpha-Al and Zn-rich eta phases, with the addition of 2 % Cu to this alloy, alpha+ eta and Cu-rich epsilon (CuZn4) were formed in addition to the existing phases. Si particles were found in the microstructure by adding 2% Si to the Zn-40Al-2Cu. Additions of Cu and Si to the Zn40Al alloy increased the BH and TS of the material while decreasing the EF. While F, Ra , and BUE decreased with increasing V in the machining of all materials, they increased with the increase in f . The addition of Cu to Zn-40Al decreased F , Ra and BUE. However, the addition of Si to Zn-40Al-2Cu increased it. While a continuous chip was formed in the machining of Zn-40Al, discontinuous chip formation was observed with Cu and Si additions. In Zn40Al alloy, f and V were found to have the highest statistical significance on F , respectively, while V x V and f x f were found to have no statistical significance using (Analysis of variance) ANOVA. On Ra , f , f x f and V were found to have the highest statistical significance, respectively, while V x V was found to have no statistical significance. In Zn-40Al-2Cu alloy, f , f x f and V were found to have equal statistical significance on F , while V x V was found to have no statistical significance. On Ra , f and f x f were found to have equal statistical significance, while V and V x V were found to have no statistical significance. In Zn-40Al-2Cu-2Si alloy, f and V were found to have equal statistical significance on F , while V x V and f x f were found to be insignificant. On Ra , f , f x f , V x V and V were found to have statistical significance, respectively. The optimum parameters for minimum F and Ra were calculated as V of 250 m/min and an f of 0.04 mm/rev. It was found that the optimum and experimental results were in good agreement with each other.