Performance Evaluation of Cutting Fluids Formulated with Recycled Toner Waste and Rice Bran Oil in Sustainable Machining of LMD Processed Ti64 Alloy

Abstract One of the greatest environmental and health risks associated with electronic waste is toner waste. Only 20–30% of global toner waste is recycled, and the rest is deposited in landfills. Owing to the desirable endurance of toners, the sophisticated combination of chemicals, carbon black, and plastic particles makes recycling difficult. The present work deals with the recycling of toner waste and its use as a cutting fluid in the machining of Laser Metal deposition (LMD)-processed titanium alloy. Although Ti-6Al-4V (Ti64) is widely utilized in various industries, including aerospace, its machinability is adversely affected by the high amount of heat generated during machining. In this study, the performance of toner waste powder (TWP) dispersed in rice bran oil (RBO) was evaluated for milling operations on LMD-Ti64 workpieces and compared with different cooling conditions. The different wt.% (0–1.00) of TWP are disseminated in RBO with glycerine (GLY) to test the contact angle, dynamic viscosity and thermal conductivity. From the test results, it is clear that 0.75 wt% of TWP with RBO + GLY gives the better results in terms of thermo-physical properties. In addition, the TWP-enriched cutting fluid improves the machining performance and surface quality in milling operations, particularly in difficult-to-cut LMD processed Ti64. The TWP-MQL condition reduced the surface roughness ( Ra ) by 60–64%, respectively.