Grinding mechanisms in oxygen-free surface grinding of Ti-6Al-4V

Abstract Grinding of Ti-6Al-4 V remains challenging due to low thermal conductivity, high chemical reactivity, and pronounced ductile deformation behavior. Existing research suggests that titanium oxide layers may influence grinding behavior by modifying interfacial interactions and material removal mechanisms. The experimental isolation of oxygen-related effects during grinding remains challenging, as conventional machining environments typically allow continuous oxidation of surfaces and chips. Within the research framework of the Collaborative Research Centre SFB 1368 “Oxygen-Free Production”, dry surface grinding of Ti-6Al-4 V is investigated under ambient air and strictly oxygen-free conditions using a gastight grinding setup that enables an XHV-adequate atmosphere with extremely low oxygen partial pressure. This approach allows oxygen-induced effects to be systematically suppressed and their influence on grinding behavior to be directly assessed. Process forces, surface topography, residual stresses, wheel loading, and chemical surface composition are analyzed using force measurements, optical surface measurement, X-ray diffraction, scanning electron microscopy, EDX and optical microscopy of metallographic cross-sections. The results show that grinding under oxygen-free conditions leads to increased wheel loading, higher and more unstable forces, wave-like surface topographies, elevated tensile residual stresses, and increased surface roughness. These effects are attributed to the absence of process-induced oxide formation, which promotes adhesion and shifts the process from cutting to being more friction-dominated. These findings demonstrate that oxidation during grinding plays a critical role in stabilizing material removal mechanisms in titanium grinding.