Yeast-based metalworking fluid for milling of titanium alloy — An example of bio-integration

Abstract

This paper reports on a study undertaken to investigate the notion that significant performance benefits can be derived through the “biologicalisation” of advanced manufacturing systems. In particular, the main objective was to apply a bio-integration approach to test whether mineral oil in conventional metalworking fluids (also commonly referred to as cutting fluids) can be substituted with suitable microorganisms without negatively affecting the performance of the fluid. Two yeast strains were used as primary compositional element in custom-prepared metalworking fluids (MWF) and tested in full-scale high-speed milling of Ti6Al4V titanium alloy with flood cooling delivery, representative of industrial applications. It is shown that both yeast strains provided similar or better performance in terms of cutting forces, tool wear and workpiece surface finish compared to a mineral oil-based reference MWF. New insights into the working mechanisms of the yeast-based MWFs as well as their composition are discussed, based on microscopy and chemical analyses. The results provide early stage evidence for a significant potential to reduce or even eliminate the use of mineral oils in metalworking fluids, with substantial benefits in process efficiency, health and safety for machine operators, and sustainability through the use of renewable and benign materials.