Machinability improvement and sustainability assessment during machining of AISI 4140 using vegetable oil-based MQL

The ecological and economic problems associated with conventional cutting fluids can be resolved by identifying a sustainable and improved cooling/lubrication approach. The vegetable oil-based minimum quantity lubrication has a good amount of acceptability toward achieving sustainable and eco-friendly machining. This work investigates the efficacy of vegetable oil-based MQL (VMQL) and minimum quantity solid lubricant (MQSL) during turning AISI 4140 steel with coated carbide tools compared to dry and wet machining. Various sustainable aspects such as machining efficiency, total energy consumption, carbon emission, and various performance indicators such as surface roughness, chip-tool interface temperature, and tool life are evaluated under selected cooling/lubricating conditions. The experimental findings showcased the superiority of VMQL and MQSL in the form of improved machining performance compared to dry and wet machining. Noticeable reduction in surface roughness up to 27% and 20% at cutting speed 100 m/min and 45% and 41% at cutting speed 170 m/min is achieved with VMQL and MQSL, respectively. Furthermore, VMQL and MQSL reduced energy consumption by 33% and 28% at lower MRR and 26% and 22% at higher MRR, respectively, compared to dry machining. The results showcased the ability of VMQL in machining to achieve sustainability and energy-saving with improved product quality.

Automated summary

The study examines the effectiveness of vegetable oil-based minimum quantity lubrication and minimum quantity solid lubricant in turning steel, showing significant improvement in machining performance compared to dry and wet machining. It demonstrates the ability to reduce surface roughness and energy consumption while achieving sustainability and energy-saving in machining.