A first approach to characterize the surface integrity generated by ball-end finishing milling

A simplified procedure is proposed to predict the surface integrity of complex-shape parts generated by ball-end finishing milling. Along a complex cutting path, the tool inclination may vary within a large range. A geometrical study is performed to predict the effect of the tool inclination (lead angle) on the micro-geometry of the machined surface and on the effective cutting speed. This geometrical study brings out a range of values of the lead angle for which the machined surface is damaged by cutting pull-outs. This geometrical study also brings out a range of values of the lead angle for which the effective cutting speed is null. This case corresponds to extreme values of the cutting forces and to high compressive residual stresses. These predictions are verified for a selection of tool inclinations and other cutting parameters such as cutting speed, feed per tooth and cusp height. These machining tests are performed on a high-strength bainitic steel. The experimental campaign includes milling tests with cutting forces measurements, 2-D optical micro-geometry measurements and X-ray diffraction measurements.

[1]  M. Bacher-Höchst,et al.  Very high cycle fatigue properties of bainitic high carbon–chromium steel , 2009 .

[2]  Jérôme Limido,et al.  Modelling the influence of machined surface roughness on the fatigue life of aluminium alloy , 2008 .

[3]  C. Lartigue,et al.  Surface topography in ball end milling process: Description of a 3D surface roughness parameter , 2008 .

[4]  J. Paulo Davim,et al.  Machining : fundamentals and recent advances , 2008 .

[5]  Jean-Hugues Marchese.  Spécification géométrique des produits (GPS) , 2015, Fonctions et composants mécaniques.

[6]  Shreyes N. Melkote,et al.  Effect of surface integrity of hard turned AISI 52100 steel on fatigue performance , 2007 .

[7]  Hédi Hamdi,et al.  Residual stresses computation in a grinding process , 2004 .

[8]  Richard K. Leach,et al.  Fundamental Principles of Engineering Nanometrology , 2009 .

[9]  Manuel François,et al.  Residual stresses and crystallographic texture in hard-chromium electroplated coatings , 1997 .

[10]  Yean-Ren Hwang,et al.  Impact of various ball cutter tool positions on the surface integrity of low carbon steel , 2009 .

[11]  Franck Morel,et al.  The anisotropic fatigue behavior of forged steel , 2009 .

[12]  H. Sasahara.  The effect on fatigue life of residual stress and surface hardness resulting from different cutting conditions of 0.45%C steel , 2005 .

[13]  Masaki Nakajima,et al.  Effect of surface roughness on step-wise S–N characteristics in high strength steel , 2003 .

[14]  Dwayne Arola,et al.  Estimating the fatigue stress concentration factor of machined surfaces , 2002 .

[15]  J. Lebrun,et al.  Influence of machining by finishing milling on surface characteristics , 2001 .

[16]  Claire Lartigue,et al.  Characterization and influence of defect size distribution induced by ball-end finishing milling on fatigue life , 2011 .

[17]  David K. Aspinwall,et al.  The influence of cutter orientation and workpiece angle on machinability when high-speed milling Inconel 718 under finishing conditions , 2007 .

[18]  D. Axinte,et al.  Surface integrity of hot work tool steel after high speed milling-experimental data and empirical models , 2002 .

[19]  David K. Aspinwall,et al.  The effect of machined topography and integrity on fatigue life , 2004 .

[20]  D. Umbrello,et al.  Experimental and numerical modelling of the residual stresses induced in orthogonal cutting of AISI 316L steel , 2006 .

[21]  Sang-Moon Hwang,et al.  Chip load prediction in ball-end milling , 2001 .

[22]  Wilfried Eichlseder,et al.  The effect of machining on the surface integrity and fatigue life , 2008 .

[23]  Hédi Hamdi,et al.  Workpiece Surface Integrity , 2008 .