Evaluation of Residual Stresses in Low, Medium and High Speed Milling

F. V. Díaz ； C. A. Mammana ； A. P. M. Guidobono

《Research Journal of Applied Sciences, Engineering and Technology》 11卷3期 (2015/09) Pp. 252-258

並列摘要

A micro-indent method is used to evaluate different residual stress states, which were generated in samples of AA 7075-T6 aluminium alloy milled at low, medium and high speed. The milling tests were carried out in order to introduce, in each new surface, two different zones from asymmetries in the orientation of the cutting edge. The results obtained in samples subjected to different combinations of process parameters reveal, in both cutting zones, compressive normal components regardless of the evaluated direction. This study includes a comprehensive analysis of the medium normal component of residual stress. This component is the most representative of the stress tensor since it is independent of the diameter of the stress circle, commonly denominated Mohr's circle. In addition, this component is associated to those directions where tangential components reach their maximum. From the sensitivity of the used method, it was possible to detect differences generated between the levels reached by the medium component in the evaluated zones. It is noteworthy that the detected differences are independent of the cutting speed and feed rate. This significant fact, finally, would indicate similar differences in the combination of local plastic deformation and heat conducted to the new surface between both cutting zones, which is valid for different combinations of process parameters evaluated in this study.

並列關鍵字

Aluminium alloy ； indent method ； milling ； mohr's circle ； residual stresses