International Journal of Modern Manufacturing Technologies ISSN 2067–3604, Vol.XII, No. 1 / 2020 36 OPTIMIZATION OF MACHINING PARAMETERS ON TEMPERATURE RISE IN CNC TURNING PROCESS OF ALUMINIUM 6061 USING RSM AND GENETIC ALGORITHM Mahesh Gopal Department of Mechanical Engineering, College of Engineering and Technology, Wollega University, Nekemte, Ethiopia Corresponding author: Mahesh Gopal, doctorgmahesh@gmail.com Abstract: In this present study, the predictive model is developed to observe the effect of nose radius to predict temperature rise on the CNC turning process and to better understanding on the effect of the machining parameters such as cutting speed, feed rate, depth of cut and nose radius. The experiments are conducted as per design of experiments of response surface methodology (RSM) by taking into consideration of aluminium - Al 6061 as workpiece material and Al 2 O 3 coated carbide tool as a cutter. A second order mathematical model was developed. The Analysis of Variance (ANOVA) was used to study the performance characteristics of turning operation. The value of probability (F) is less than 0.05 indicates, the model conditions are significant. The cutting speed is the most significant influencing parameter compared to the other parameters. For the optimum cutting parameter leading to temperature rise, the genetic algorithm model is trained and tested in MAT Lab. The genetic algorithm recommends 23.94°C as the best minimum predicted value. The confirmatory test shows the predicted values which were found to be in good agreement with observed values. Key words: Aluminium 6061, Cutting speed, Feed rate, Depth of cut, Nose radius, Genetic Algorithm, Response surface methodology, Temperature rise. 1. INTRODUCTION Machining is the term used for removal of material from the workpiece, for cutting the workpiece generally single point cutting tool or multi point cutting tool is used. Surface roughness, tools wear, chip morphology, residual stresses and temperature generated during machining is suggested by many researchers (Powar and Raval, 2016). During machining, the cutting zone temperature is very high and the majority of the heat from the cutting operation carried out by the chip. Tremendous amount of temperature increases tool wear, reduces tool life and poor surface finish, so proper selection of cutting conditions and careful attention must be well thought-out while selecting cutting speed, depth of cut, feed rate, type of lubrication, cutting tool material, cutting tool angle etc. The high-quality machinability improves the reduction of the tool wear, cutting forces, cutting temprature, and a better control of the chip. An improvement in machinability produces a considerable improvement of the surface finish. During the cutting operation, cutting tools are subjected to friction which results temperature rise, less accuracy and poor surface roughness Santos et al., (2011). According to the relative motion between the tool and workpiece, the tool, workpiece surface integrity and machining precision are directly affected by the cutting temperature, (Ming et al., 2003). Temperature in the cutting zone depends on contact length between tool and chip, cutting forces and friction between tool and work material (Ejieji et al., 2018). The quality of machined surface and optimal cutting temperature decide by the combination of tool and work material, the geometry of cutting tool, chip control, magnitude and the direction of cutting force, stabilized cutting force. (Astakhov, 2010) used a technique to investigate the influence of temperature on the tool wear, during high speed turning of Inconel 718 and high - speed milling of Ta6V alloys. The thermocouple consisted of a tungsten wire, which was embedded in the tool. (Sullivan and Cotterell, 2001) measured by using two thermocouples of temperatures while turning of aluminum 6082-T6. They indicated that an increase in cutting speed resulted in a decrease of the temperature in machined surface. The author recognized the reduction in temperature at higher metal removal rate, which results more heat dissipated away by the chip and results less heat being by the workpiece. The author Ceau et al., (2010) investigated that the turning operation of unalloyed steel, the natural and artificial thermocouple, infrared camera and optical pyrometer is used to measure the temperature of the tool and suggests that the temperature depend on the parameters of the cutting process. To analyze the influence of the cutting parameters the mathematical regression technique was used to predict temperature. 1.1 Influence of nose radius in turning tool The point of intersection of tool point (rake surface, principal flank surface, auxiliary flank surface) surfaces gives rise to the tool tip. A small radius provided in the