## 3 Results
### Temperature Distribution from CEL-Simulation  
With the simulation described above, the temperature distribution at the cutting edge is examined. An orthogonal cut was used to find out the necessary fineness of the mesh required for the workpiece over the depth of cut. Values frequently used in the literature represent an orthogonal cut that has at least four nodal points above the height of the infeed in order to obtain a sufficiently accurate result of the cutting simulation. The number of elements was varied over the feed in 4 and 10 elements. The result is that a nice chip formation occurs with 10 elements over the infeed as can be seen in Figure 9a. The rake angle of the tool is 0\({}^{\circ}\) and does not vary, regardless of whether considering the real process or the orthogonal cut, with a wedge angle of 75\({}^{\circ}\). The 2D cutting process cannot feature the differing angles of the cutting insert, with a wedge angle varying between 75\({}^{\circ}\) and 83\({}^{\circ}\). For simplicity of the examination in a 2D cut, there is also no chip groove given at the tool. Figure 9b shows the difference of the temperature evolution with respect to the number of elements, which are in contact with the tool. The temperature differences are observed at a similar level for 4 elements as for 10 elements. A number of 10 elements over the infeed \begin{table}
\begin{tabular}{c c c} \hline \hline
**Specific Heat \(\epsilon_{c}\)/J/kgK** & **Conductivity \(k\)/W/mK** &
\begin{tabular}{c} **Heat Transfer Coefficient** \\ **a/W/mm\({}^{2}\)** K \\ \end{tabular} \\ \hline
436 & 106.1 & 313.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Thermal parameters obtained by optimization from the cooling step. Figure 7: Temperature evolution of the hot air soldering station experiment. only has a small impact on the resulting temperatures in the workpiece. In addition, the effect of MS was considered. In general, a lower heating rate of tool and workpiece material can be observed with increasing mass scaling. The resulting absolute temperatures with a MS factor of \(10^{5}\) are only slightly influenced by the number of elements in the depth of the cut. The influences on the temperatures shown are noticeable, but the settings have a very significant effect on the calculation times. In addition, such temperature differences do not have a large effect on the cutting process, also because the temperatures are still far from the melting temperature of the material. The effect of a lower heating rate with increasing mass scaling is negligible. The drilling process runs for several seconds to minutes, where a constant temperature is considered. The advantage of the CEL-simulation method is the realistic representation of feed and cutting speed with simultaneously acceptable calculation times. Thus, the cutting speed is set to \(v_{c}\) = 80 m/min and die feed to \(f\) = 0.05 mm/rev. The resulting temperatures are shown in Figure 10 at different times. Due to the mesh fineness of four elements above the infeed, no ideal chip formation occurs. It looks similar to a tough friability of the workpiece material. The highest temperature develops in the outer cutting edge of the cutting insert. This can be deduced from the relative velocity, which is the highest at this point. Figure 8: (**a**) Temperature evolution of the heating process, (**b**) Temperature evolution of the cooling process. Figure 9: (**a**) Orthogonal cut using CEL-method, \(t_{sim}\) = 0.0015 s, \(v_{c}\) = 80 m/min, \(a_{p}\) = 0.05 mm, mass scale MS = 0 (**b**) Temperatures of the orthogonal cut with a difference in mesh fineness and mass scaling. After a simulation time of \(t_{sim}\) = 0.5 s, the temperature distribution of the cutting insert is exported and used as a reference for the temperature at the cutting edge and presented in the form of exponential equations. The heat transfer from the cutting edge to the sensor positions is a transient heat conduction process in which a time-dependent temperature field is established.