Experimental investigation of the simultaneous effect of machining parameters, axial force and cutting torque on the surface roughness of the produced hole in the drilling of the 7000 series AL Alloy workpiece

One of the most important parameters that can be considered when creating a hole is the surface roughness. Many factors, such as drill transverse vibration, temperature, and tool geometry, play a role in creating surface roughness. In this paper, the effects of the factors include spindle speed, feed and pre-drill with associated variables including axial force and cutting torque are considered. The main purpose of this paper is to determine the significance of each of the factors and dependent variables in the variation of surface roughness. The material of workpiece is selected from the 7000 series Al Alloy. The simultaneous analysis of all the factors and dependent variables has been done using the Manova method. In the first step, the results show that the use of this method can reveal the effect of factors on creating simultaneously the axial force and cutting torque, and then determines the effectiveness of each of the factors and dependent variables in determining the surface roughness at 95% confidence level. The results indicate that considering axial force and cutting torque in model can increase the ability of prediction model in surface roughness by 37.39% compared to the prediction performed based on factors. On the other hand, the results show that the axial force has a greater effect than the cutting torque on the surface roughness of the hole. Therefore, in order to improve the surface quality of the produced hole, it is necessary to pay attention to methods that reduce the axial forces.