Metal working fluids in machining operations, also called cutting fluids (CFs), accomplish the main functions of lubrication between the tool and the work material, cooling down the cutting zone, and washing away the chips from the cutting area. Traditional CFs are either entirely based on mineral oils or, for water-based CFs, contain up to 10% mineral oils. Over time, CFs become contaminated by foreign substances, including bacteria and fungi, causing rancid odour in the work environment and health hazards for the machinists; this contamination is countered by adding biocides, which in turn can be polluting and unhealthy. Conventional CFs, therefore, are potentially pathogenic for humans, deteriogenic for the environment, and costly to dispose of due to the mineral oil and biocide contents. As the global CF consumption amounts to over two million tons/year, the development of greener, more sustainable CFs is highly desired in the manufacturing industry. In this paper, the replacement of mineral oil in CFs with suitable microorganisms providing the lubrication function is studied within a bio-integrated manufacturing approach, with the aim to markedly reduce the negative impact conventional CFs on environment and human health. The turning trials were performed on AISI 1045 steel bars under Small Quantity Lubrication (SQL) conditions using a microbial-based CF containing a microalgae species as lubricant component. The viability and effectiveness of utilising the novel microbial-based CF was positively demonstrated. The cutting forces, tool wear level, surface finish and dimensional accuracy achieved with the microbial-based CF were comparable to or better than for dry cutting and conventional CF.

加工操作中的金属加工液也称为切削液（CFs），其主要功能是润滑工具与工作材料之间的润滑，冷却切削区域并从切削区域冲洗掉切屑。传统的CF要么完全基于矿物油，要么对于水基CF最多包含10％的矿物油。随着时间的流逝，CFs会被包括细菌和真菌在内的异物污染，在工作环境中产生恶臭气味，并对机械师产生健康危害；通过添加杀菌剂可以抵消这种污染，杀菌剂又会造成污染并且不健康。因此，常规的CFs可能对人类有致病性，对环境具有致死性，并且由于矿物油和杀生物剂的含量，其处置成本很高。随着全球CF消费量超过200万吨/年，在制造业中迫切需要开发更绿色，更可持续的CF。在本文中，以生物集成制造方法研究了用具有润滑功能的合适微生物替代CF中的矿物油，目的是显着减少常规CF对环境和人类健康的负面影响。车削试验是在AISI 1045钢筋上使用少量基于微藻的微生物CF作为润滑剂组分，在少量润滑（SQL）条件下进行的。积极证明了利用新型微生物基CF的可行性和有效性。切削力，刀具磨损水平，