Analysis of surface roughness and energy consumption in turning of C17500 copper alloy under different machining environments and modellings with response surface method

The difficulties in machinability due to the developments in the technical properties of engineering materials increase the importance of machinability indicators such as surface quality, power or energy consumption and tool life in terms of sustainable machining. In this context, the machinability of a copper-beryllium alloy (C17500), which is used in a wide range of industries and also characterized as a hybrid material, was investigated in vortex tube cooling and dry cutting environments. First, turning experiments were performed with a coated carbide tool and varying cutting speed, feed rate and depth of cut. In the experiments, the total energy consumed during turning and the roughness of the machined surfaces were measured, and analysed experimentally and statistically. In the second stage, mathematical models were developed for the total energy consumption and average surface roughness for both cutting environments with the response surface method. As a result, the chip formation process in the turning of the Cu alloy under vortex tube cooling negatively affected the cutting power and positively contributed to the surface quality. Due to the fact that vortex tube cooling creates a cooling effect rather than lubrication, built-up layer/built-up edge (BUL/BUE) formation on the tool cutting edges caused the change in the tool geometry and thus the chip removal process became more difficult and increased the energy consumption. On the other hand, in the vortex tube cooling application, the surface roughness decreased by an average of 31.4% compared to dry cutting. Furthermore, the predictive mathematical models developed for the total energy consumption and the mean surface roughness can be used with high reliability.