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Machining operations like milling exhibit complex process kinematics, which restricts the identification and analysis of fundamental cause-effect interrelations. In order to differentiate the impact of relevant process parameters, a reduction of influencing factors is necessary. For this purpose, a cutting operation with a linear cutting motion, like orthogonal cutting, is beneficial. Such an experimental setup requires suitable tools, workpieces and measurement systems. The experimental assessment of a developed modular design is presented in this publication. In addition to orthogonal cuts, oblique cuts, which are representative for machining operations with respect to the helix angle, were investigated. To analyze process dynamics, interrupted cuts, including a specifically compliant tool system, were performed.

The quality and surface integrity of machined parts is influenced by residual stresses in the subsurface resulting from cutting operations. These stress characteristics can not only affect functional properties such as fatigue life, but also the process forces during machining. Especially for orthogonal cutting as an appropriate experimental analogy setup for machining operations like milling, different undeformed chip thicknesses cause specific residual stress formations in the subsurface area. In this work, the process-related depth profile of the residual stress in AISI 4140 was investigated and correlated to the resulting cutting forces. Furthermore, an analysis of the microstructure of the cut material was performed, using additional characterization techniques such as electron backscatter diffraction and nanoindentation to account for subsurface alterations. On this basis, the influence of process-related stress profiles on the process forces for consecutive orthogonal cutting strategies is evaluated and compared to the results of a numerical model. The insights obtained provide a basis for future investigations on, e. g., empirical modeling of process forces including the influence of process-specific characteristics such as residual stress.