Investigation of the cutting fluid's flow and its thermomechanical effect on the cutting zone based on fluid-structure interaction (FSI) simulation

Cutting fluids are an important part of today's metal cutting processes, especially when machining aerospace alloys. They offer the possibility to extend tool life and improve cutting performance. However, the equipment and handling of cutting fluids also raises manufacturing costs. To reduce the negative impact of the high cost of cutting fluids, cooling systems and strategies are constantly being optimized. In most existing works, the influences of different cooling strategies on the relevant process state variables, such as tool wear, cutting forces, chip breakage, etc., are empirically investigated. Due to the limitations of experimental methods, analysis and modeling of the working mechanism has so far only been carried out at a relatively abstract level. For a better understanding of the mechanism of cutting fluids, a thermal coupled two-dimensional simulation approach for the orthogonal cutting process was developed in this work. This approach is based on the Coupled Eulerian Lagrangian (CEL) method and provides a detailed investigation of the cutting fluid's impact on chip formation and tool temperature. For model validation, cutting tests were conducted on a broaching machine. The simulation resolved the fluid behavior in the cutting area and showed the distribution of convective cooling on the tool surface. This work demonstrates the potential of CEL-based cutting fluid simulation, but also pointed out the shortcomings of this method.