Surface roughness and vibration analysis in end milling of annealed and hardened bearing steel

This experimental study involves statistical analysis, mathematical modeling and optimization of machined surface roughness (Ra) well as the level of workpièce displacements (D) recorded during the shoulder and contour milling of AISI 52100 bearing steel. Dry end milling of annealed and quenched/tempered condition with TiAlN coated carbide inserts tool. A Taguchi experimental plan of 27 tests was adopted to determine the influence of the cutting parameters (Vc, fz, ae) considered as input factors, surface roughness and level of workpiece throbs/displacements considered as response factors recorded during machining. To show the degree of influence of each cutting parameter on the milled surface roughness and displacements, analysis of variance and mathematical regression models were adopted. The objective of this study is to see the influence of the radial depth of cut ae during shoulder, grooves and contour milling when we have a strong ap and a weak ae. Usually when face milling, we adopt a strong ae and a low ap. The experimental results obtained shown that for two states of steel tested that the cutting speed and feed per tooth is the most influencing factor on the milled surface roughness Ra evolution. Radial depth of cut influences considerably the level of displacements. Multi-objective optimization gave the desired cutting conditions with a desirability function DF ​= ​0.897. © 2020 The Authors