Microbial-based metalworking fluids in milling operations

Most commercial metalworking fluids (MWFs), as applied in cutting operations contain mineral-oil. Colonization of water-based MWFs by microorganisms is considered a problem due to metabolism of the MWF components. This paper presents a paradigm shift by exploiting the potential of substituting oil-containing water-based MWFs in machining processes by microbial-based fluids. For the first time, specifically selected microorganisms have been applied in milling experiments and were examined regarding their lubrication performance. Compared to conventional water-based MWFs a prolonged tool life and superior surface finish were obtained in milling. From the results, the working mechanisms of microbial-based MWFs are deduced and discussed.