Assessment of surface roughness and MRR while machining brass with HSS tool and carbide inserts

Abstract

This work focuses on study of surface roughness (Ra ) and metal removal rate (MRR) produced in hard turning process under dry conditions using TiN-Al2O3 -TiCN-TiN coated carbide inserts and high speed steel (HSS) tools. Two parameters are selected for the study: speed and feed with constant depth of cut. These machining parameters are adopted to analyze their influences, significance and contributions on the generated surface roughness and MRR. Full factorial design of experiments (DOE) is used for conducting the experiments and analysis of variance (ANOVA) is used to assess the significance and contribution of each parameter and also their interactions. Later, the optimal parameter combinations for generating surface roughness and MRR are determined. The data generated using DOE is used for regression analysis and to create model for predicting the average surface roughness and MRR as a function of speed and feed. A confirmation experiments are done yielding max of 5.93% and 6.17% error in regression, while machining with carbide and HSS tools respectively. Surface roughness of 1.42 µm and 2.37 µm while machining with carbide and HSS tools respectively are obtained at the optimal combination of machining parameters.