Proceedings of SerbiaTrib '13

Figure 7. Accumulated tool life in milling of theemployed hardened steel IMPAX versus the entryimpact duration at various cutting speedsfunction of the cutting speed and the entry impactduration is:T0.15C3( v,te) CC41teC2e(1)The parameters C 1 , C 2 , C 3 and C 4 depend on thecutting tool and workpiece material data. Moreover,these parameters are functions of the cutting speedand the entry impact duration.Considering the entry impact duration, usingequation (1), the cutting tool life T 0.15 up to a flankwear land width VB equal to 0.15 mm can beestimated. Moreover, the number of cuts NC 0.15corresponding to a flank wear land width VB equalto 0.15 mm can be calculated based on theundeformed chip length and the cutting speed usingthe relation (2).T0 .15 NC0.15 lcuv (2)Bearing in mind that a number of cuts equal tozero corresponds to a tool wear VB also equal tozero and the number of cuts NC 0.15 is associated toVB equal to 0.15 mm, the evolution of the toolwear during milling can be calculated as describedin [9].6. COMPUTATION OF THE TOOL WEARIN MILLING AT CHANGEABLECUTTING CONDITIONSDuring milling a workpiece, the values ofparameters influencing the tool wear developmentsuch as chip length, chip thickness, entry impactduration etc. may vary in the successive tool paths.Considering these circumstances, for computing thetool wear developed during milling, themethodology explained in Figure 9, is applied [15,16].Figure 8. Accumulated tool life in milling of theemployed hardened steels versus the entry impactduration at various cutting speedsThis is due to comparatively higher hardness ofNIMAX. Moreover, it is obvious that due toreasons described in [11, 12, 13, 14] stainless steelis difficult to cut.5. THE DEVELOPED MODEL FORDESCRIBING THE WEAR EVOLUTIONON COATED TOOLS IN MILLING BASEDON CUTTING EDGE ENTRY IMPACTDURATIONThe general form of the equations, shown inFigure 7, describing the accumulated tool life as aFigure 9. Determination of tool wear evolution inmilling at various cutting conditions13 th International Conference on Tribology – Serbiatrib’13 17