Proceedings of SerbiaTrib '13

Figure 13. Calculated and measured flank weardevelopment versus the number of cuts8. CONCLUSIONSFigure 12. Histograms of the entry impact durationalong the tool pathsCharacteristic results of this methodology aredisplayed in Figure 12, where histograms of theentry impact time of the removed chips in both upand down milling kinematics are illustrated.In up milling almost all chips were cut at impactduration of approximately 4,8 ms. In contrary,when down milling is applied almost half chipspossess entry impact durations of less than 4 ms,while some of them are associated with impactdurations less than 1 ms. In this way, it is expecteda more intense wear evolution in down millingcompared to up one.It is has to be pointed out, that the more intensetool wear evolution in down milling of thisparticular test part compared to the up one, cannotstand for every milling case and depends on theworkpiece and the tool edge geometry and materialdata.For calculating the tool wear developed duringmilling of the test part, the introduced method inprevious paragraph was used. The flank wear landwidth VB versus the number of cuts NC wascalculated and experimentally detected. Themeasured and the calculated values of the tool wearevolution in both milling kinematics are presentedin Figure 13. The experimental results convergesufficiently with the calculated ones.The results described in this paper show thesignificant effect of the cutting edge entry impactduration on the coated tools wear evolution inperipheral and face milling. The effect of cuttingedge entry impact duration on the coated toolfatigue failure was investigated via an impact testerwith force signal modulation facilities. Moreover,based on the cutting edge impact duration, acalculation of the expected tool wear developmentcan be carried out. In this way, the selection ofoptimum cutting conditions and strategies inmilling with coated tools can be achieved.REFERENCES[1] H.-J. Jakobs, P. Winkelmann: AktuelleStandzeitfunktion für die Arbeitsgestaltung beimFräsen, Fertigungstechnik und Betrieb, Vol. 31, pp.352–356, 1981.[2] L.J. Dammer: Ein Beitrag zur Prozessanalyse undSchnittwertvograbe beim Messerkopfstirnfräsen,Dissertation, RWTH Aachen, 1982.[3] K.-D. Bouzakis, S. Makrimallakis, G. Katirtzoglou,E. Bouzakis, G. Skordaris, G. Maliaris, S. Gerardis:Coated tools’ wear description in down and upmilling based on the cutting edge entry impactduration, CIRP Annals - Manufacturing Technology|Vol. 61, No. 1, pp.115-118, 2012.[4] Bouzakis K.-D, Gerardis S, Katirtzoglou G,Makrimallakis S, Michailidis N, Lili E., IncreasingTool Life by Adjusting the Milling CuttingConditions According to PVD Films’ Properties,CIRP Annals – Manufacturing Technology, Vol.57, No. 1, pp.105–108, 2008.13 th International Conference on Tribology – Serbiatrib’13 19