Coated CBN cutting tool performance in green turning of gray cast iron EN-GJL-250: modeling and optimization

Abstract

The present research investigates the performance of a TiN/PVD-coated CBN7050 tool when turning the gray cast iron EN-GJL-250. This is performed through carrying out two series of tests. The first are parametric tests aiming at evaluating the effect of each cutting parameter, i.e., the cutting speed, the feed rate and the depth of cut on the cutting forces, the cutting pressure, the surface roughness, and the cutting power. The second series of tests concern the modeling that would lead to predicting the output parameters. Both the analysis of variance and the response surface methodology are selected to develop the relationship between the input factors (Vc, f, and Doc) and the output parameters. The tests are carried out according to the Taguchi design (L27). The derived models are used to perform a multi-objective optimization of the cutting parameters through the application of the desirability function approach (DFA) for four objectives. Furthermore, the CBN7050 tool wear behavior was investigated during the machining of gray cast iron EN-GJL-250. Tool lives reached 7, 18, and 41.5 min when Vc was varied from 450, 600, to 750 m/min, respectively. Finally, a topographical analysis of the machined surface 3D roughness was carried out for different cutting parameters and led to displaying the texture of the surfaces.