A RESIDUAL-STRESS MODEL FOR THE MILLING OF ALUMINUM-ALLOY (2014-T6)

One of the important problems encountered in the milling processes is the elastic deformation of the workpiece; thus, how to select the cutting parameters to reduce the residual stress is especially crucial. A mathematical model is presented for predicting the residual stresses of alloy 2014-T6 caused by end-milling. Factors such as the cutting conditions (cutting speed, feed, and cutting depth) and the tool geometries (tool nose radius and flank wear) are considered in this paper. To reduce the number of experiments required and to build the mathematical model for these variables, Response Surface Methodology (RSM) with the Takushi method are used. In addition, variance analysis and an experimental check are conducted to determine the prominent parameters and the adequacy of the model, According to the above processes, it is shown that the cutting speed, feed, tool nose radius and flank wear have the most significant effect on the residual stresses and there is an interaction between the cutting speed and flank wear, The affect on the residual stress of the cutting conditions and tool geometries can be explained in terms of the cutting force, the rise in temperature and the microstructure variation. Therefore, this model, offering good correlation between the experimental and predicted results, is useful in selecting suitable cutting parameters for the machining of alloy 2014-T6.