Influence of an Oxygen‐Free Atmosphere on Diamond‐Single‐Grain Scratching of Ti–6Al–4V

This study introduces a newly developed experimental setup for investigating the influence of controlled atmospheric conditions on single‐grain scratching of Ti–6Al–4V using natural diamond grains. The setup enables experiments under air, argon, and argon–silane atmospheres, allowing targeted investigation of oxygen‐related effects on material removal. High‐speed imaging captures chip formation and chip‐grain interactions during the process, while scanning electron microscopy and metallographic analysis provide complementary information on grain condition and material adhesion. Validation experiments demonstrate reliable and repeatable scratching under oxygen‐reduced and oxygen‐free conditions. Within the investigated parameter range, the measured normal and tangential forces show no clearly distinguishable systematic dependence on atmosphere, although potential effects may be masked by variations in grain geometry and effective depth of cut. In contrast, pronounced differences in chip adhesion behavior are observed. In ambient air, rapid chip detachment is promoted, associated with formation of a thin passivating titanium oxide layer. Under oxygen‐reduced conditions, suppressed oxidation leads to increased adhesion and local material accumulation on the grain. Overall, the results confirm the suitability of the methodology for in situ investigation of atmosphere‐dependent mechanisms and provide a foundation for future studies on oxygen effects in grinding and related machining processes.