Metal işleme işlemlerinde üç boyutlu sıcaklık ve kalıntı gerilimi tahmini

The purpose of the first part of this study is to determine the three dimensional temperature fields on the chip, tool and workpiece during machining, which is one of the most important characteristic of machining processes; since the fields can affect other properties such as residual stresses and tool wear, and thus tool life and fatigue life of finished parts. The finite difference based model proposed in this paper offers very rapid solutions that are reasonably accurate with experiments. Finite difference based simulation results are validated with infrared thermal measurements which are determined from the machining of Al 7075, AISI 1050 and AISI H13 materials under various cutting conditions. The second part of this study deals with the prediction of residual stresses in machining processes. To result in the residual stresses after machining, two-dimensional cutting temperatures are predicted on the chip, tool and workpiece, using the cutting forces as the cause for heat generation. An analytic elasto-plastic model is implemented on the superposition of thermal and mechanical stresses on the workpiece, and a relaxation procedure is applied, using kinematic and isotropic hardening together, resulting in the residual stresses on the workpiece. Results are verified with experimental data on residual stresses on Waspaloy, and accurate results are achieved, while the computational time to predict the residual stresses is immensely decreased, compared to FEM studies within literature.