Optimization of Surface Roughness and Metal Removal Rate in End Milling using Taguchi Grey Relational Analysis

Objectives: The objective of the present work is to assess the effects of machining parameters in milling on surface roughness and metal removal rate of AISI H11 steel. It is used in the manufacturing industries for making die casting moulds, extrusion dies, moulds for glass industry, punches, piercing tools, mandrels etc. Methods/Statistical Analysis: The objective of the study was carried out by machining experiments which were conducted on CNC vertical milling machine whose maximum speed was 6000 RPM. Design of experiments based on Taguchi grey relational analysis with three independent factors (cutting speed, feed rate and depth of cut), three levels L27 orthogonal array has used to develop relationships for predicting surface roughness and metal removal rate. Findings: The surface roughness was measured using surface roughness tester (Mitutoyo surftest-4) and the averages were calculated to obtain the surface roughness of the samples. Metal removal rate was calculated using the formula in terms of width of cut, depth of cut and table feed rate. Improvements: Model significance tests were conducted using ANOVA table and effects of various parameters were investigated.