Work

Environmentally sustainable EDM of Ti-6Al-4V alloy employing copper nanoparticle-dispersed vegetable oil dielectrics

Year: 2025

Type: article

Abstract: • EDM-based surface finishing of Ti-6Al-4V using biodegradable dielectrics • Sesame oil with Cu nanopowder in EDM achieved the highest MRR of 9.24 mm³/min • The lowest surface roughness was achieved with sunflower oil dielectric • Olive oil dielectric provided the lowest specific energy consumption (161.51 J/mm³) • Biodegradable dielectrics improved SR, MRR, SEC, and olive oil cut CO₂ by 84.1% Titanium-based alloys are widely recognised for their exceptional stability in harsh environments and outstanding mechanical strength. However, these same properties render them among the most challenging materials to machine using conventional techniques. In this context, electrical discharge machining (EDM) has emerged as a promising alternative, offering precise machining of difficult-to-cut materials while avoiding the typical problems of tool wear and thermal distortion associated with traditional processes. Despite these advantages, EDM faces critical limitations when employing hydrocarbon-based dielectric fluids such as kerosene. These fluids not only release toxic gases and increase CO₂ emissions during the discharge process but also pose serious health risks to operators and exacerbate environmental pollution. To address these challenges, the present study investigates the potential of four biodegradable, vegetable oil-based dielectrics: sunflower oil, sesame oil, olive oil, and soybean oil. In addition, copper nanoparticles were introduced into these media to enhance cutting performance. To ensure systematic and rigorous evaluation, the experiments were designed using the Taguchi method, and ANOVA further analysed the results. Three performance indicators were considered: surface roughness (SR), material removal rate (MRR), and specific energy consumption (SEC). The findings revealed notable improvements. Sesame oil achieved the highest MRR of 9.24 mm³/min, which was 74.8% higher than the lowest MRR obtained with sunflower oil (5.28 mm³/min). The utilization of sunflower oil as a dielectric fluid resulted in a surface quality improvement of up to 20% over other dielectrics and an 11.11% enhancement compared to conventional EDM dielectric fluids. Olive oil, in contrast, demonstrated the lowest specific energy consumption (161.5 J/mm³), representing a 28.8% reduction compared with other oils, while also achieving the greatest reduction in CO₂ emissions up to 84% compared with kerosene. These results highlight the strong potential of biodegradable dielectrics in EDM, not only for improving machining efficiency but also for advancing toward a more sustainable and environmentally responsible manufacturing process.

Source: Results in Engineering

DOI: 10.1016/j.rineng.2025.108038