The objective of the subproject is to understand the interactions between atmosphere, local contact and friction conditions, thermomechanical tool load and achievable surface and subsurface properties during cutting of titanium. For this purpose, in situ investigations are carried out using a high-speed and a thermographic camera. Based on the gained data, models will be developed that predict the tool wear considering the atmosphere-specific wear mechanisms and the atmosphere-specific surface topography of machined components.