A hybrid numerical and experimental approach towards Ti6Al4V alloy sustainable orthogonal turning

Abstract

By 2030, United Nations members should modernize their manufacturing systems to make them more sustainable and resilient. In machining this includes, managing consciously the type and amounts of metalworking fluids (MWFs), as well as the delivery systems. Indeed, shifting from flood cooling with mineral-based emulsions to near-dry methods, such as minimum quantity lubrication (MQL) is crucial to increase sustainability. Thus, the objective of this study was to determine the conditions (feed and speed) for Ti6Al4V orthogonal turning where the use of MQL was found to be more effective than flood cooling. To attain that, digital twins were created to study key process responses, such as cutting force, cutting power, specific cutting force, peak tool temperature, chip curling radius, and material removal rate. The numerical database was used to find optimal conditions, which were reproduced experimentally. The friction coefficient, tool-chip contact length, and chip morphology were studied experimentally and used to validate the digital twins. It was observed that the influence of the cutting speed and feed rate was two-folded, as they not only directly impacted the alloy thermo-mechanical response (exerting a more pronounced effect than the use of lubrication) but also played a crucial role in the effectiveness of the MQL system. Indeed, the MQL system performed better when low feed and/or speed were combined. Situated within the broader framework of cleaner production, the research highlights the transformative potential of process virtualization with digital twins in facilitating the planning and adoption of responsible fluid practices in industrial machining, essential for reducing the environmental impact of industrial machining.