Analysis of Al7136 surface roughness in end milling process based on discriminant analysis

Abstract. The objective of this research is to determine how cutting parameters influence the transversal surface roughness of Al7136 aluminum alloy when subjected to end milling. To achieve this, 150 experiments were performed, systematically varying the cutting speed (v), depth of cut (ap), and feed per tooth (fz). The method used for analysis is discriminant analysis, which generated three discriminant functions. The results indicate a significant correlation between these variables and surface roughness. The discriminant functions provided an accurate classification of observations into different levels of roughness, and the coefficients of these functions showed the relative importance of each independent variable in discriminating between different levels of roughness. Covariance and correlation analyses were performed to further understand the interactions between the independent variables within each experimental group. The conclusions suggest that adjusting cutting parameters can be performed to achieve a reduction in the roughness of the machined surface, contributing to the improvement of product quality in end milling of the Al7136 alloy.