Impact of machining parameters on surface roughness and machining forces in Al7075 turning with minimum quantity lubrication and cold fluid

Abstract

This research focuses on studying the impact of cutting parameters on surface roughness and machining forces in turning Al7075 using minimum quantity lubrication and cold fluid. Al7075 is widely used in the aerospace, automotive, and tooling and machining industries. After analyzing the machining process parameters, the input parameters chosen at three levels are cutting speed, feed rate, fluid temperature, and cutting depth. The air pressure, fluid flow rate, nozzle angle, and the distance between the nozzle and the cutting area remain constant throughout the experiment. The output data investigated in this article include surface roughness and machining forces. The Design Expert software was used, employing the response surface method, to design the experiments, analyze the results, and optimize the parameters. To reduce coolant costs, the minimum quantity lubrication method with cold fluid was employed. The results indicate that machining forces decrease at a temperature of −20°C compared to both a temperature of +20°C and dry machining. Moreover, the use of cold fluid reduces surface roughness by 38.7% and 68.3%, respectively, when compared to a temperature of +20°C and dry machining. Overall, the application of the minimal quantity lubrication method, which includes the use of cold fluid, has shown positive effects in reducing forces and surface roughness under all machining conditions.