Optimization of cutting parameters with cutting force measurement in drilling of aluminum 2024 T351 material

Machining is a very common production method. In addition, hole drilling operations constitute 33% of all machining processes and 25% of the energy consumed in all machining processes. Considering the prevalence of hole drilling in the manufacturing sector, it is aimed to reduce the cost by minimizing tool wear, energy consumption and time in hole drilling processes. This is possible by optimizing the parameters that affecting the drilling. In this study, hole drilling experiments were carried out using Al 2024 T351 alloy, which is highly preferred in the aerospace industry and therefore subjected to thousands of hole drilling processes. Optimum levels of cutting parameters were determined according to the cutting force values obtained from the experiments. Cutting speed (50, 70, 90 and 110 m/min) and feed rate (0.06/0.08/0.1 and 0.12 mm/tooth) were considered as cutting parameters. Experiments were performed separately for three tool types (HSS, HSSE-Co5, HSSE-Co5 TiAlN coated) with 8 mm diameter according to Taguchi L16(4^2) experimental design. In performing the experiments and obtaining the forces; Taksan TMC-700 V CNC vertical machining centre with FANUC control panel, ESIT AX3 load cell, NI 9237 module of NI cDAQ-9188 data acquisition unit and FlexLogger software was used. The insignificant data caused by the signal noises were tried to be reduced by applying the exponential smoothing data analysis method in Excel software to all the force data obtained in the experiments. The maximum forces in the machining direction (z-axis) were determined for each hole. Taguchi optimizations, analysis of variance (ANOVA) and regression analyses were performed with the help of Minitab 19 software using these determined maximum cutting forces. Also, multiple response optimizations (response surface method) of cutting parameters, which minimize the maximum cutting force and processing time, were carried out. Optimum levels of parameters in terms of maximum cutting force for all three tool types were determined by Taguchi optimization as 50 m/min for cutting speed and 0,06 mm/tooth for feed rate. With the help of analysis of variance, it was concluded that the most effective cutting parameter on the cutting force in all three tool types was the feed rate. As a result of the regression analysis, mathematical models describing the relationship between maximum cutting force and cutting parameters were obtained. Optimum levels of cutting parameters that minimize the maximum cutting force and processing time together were determined by multiple response optimization as 110 m/min for cutting speed and 0.06 mm/tooth for feed rate.