an experimental investigation on the effect of machining and mql parameters on the surface roughness in finish turning of al7075 alloy

Today, with increasing concerns about the harmful effects of the cutting fluids on the environment, many efforts have been made to reduce the consumption of these fluids. one proposed solution to reduce cutting fluid consumption in machining processes is using the minimum quantity of lubrication (mql) method. this method improves machining conditions by atomizing the cutting fluid and spraying it on the tool surface. in this research the effect of the mql and the machining parameters, including cutting fluid’s flow rate, mql nozzle’s air pressure, feed rate, and cutting speed on workpiece surface roughness in the turning process of aluminum alloy 7075, were investigated by employing the response surface method (rsm). based on the results of experimental tests, the lowest surface roughness obtained using parameters of the fluid flow rate of 275 ml/h, the pressure of 3 bar, cutting speed of 200 m/min, and feed rate of 0.08 mm/rev was measured as 0.438 microns. evaluating the results showed that the feed rate has a direct relationship with the surface roughness, and as the feed rate increases, the surface roughness also increases. the effect of cutting fluid’s flow rate, air pressure, and cutting speed on the workpiece surface roughness does not have a consistent trend and depends on the cutting parameters. therefore, statistical or experimental analysis methods can be utilized to achieve the optimal values of workpiece surface roughness