OBRABOTKAMETALLOV Vol. 27 No. 1 2025 technology nanofluids of different compositions. Fig. 7 illustrates the measured cutting force with varying nanoparticle concentrations (0.2 wt. %, 0.4 wt. %, 0.8 wt. %, and 1 wt. %). Graphene nanofluids provided the most significant reduction in cutting force. Using the base cutting fluid resulted in a cutting force of 135 N; however, with 0.8 wt. % graphene nanofluid, the cutting force decreased to 104 N, i.e. by 29.8 %. This is attributed to improved lubrication; nanoparticles on the metal surface formed a robust lubricant film, leading to better heat dispersion. The higher thermal conductivity and improved lubrication from increased graphene concentration reduced friction and heat generation. At 1 wt. % graphene concentration, the cutting force increased to 108 N compared to 0.8 wt. %, primarily because of nanoparticle agglomeration, which impaired the nanofluid’s performance. Fig. 7. Cutting forces when using different nanofluids The tribological properties of a component determine its ability to effectively and long-term perform its intended function in the intended application area. Surface quality is a key factor influencing tribological characteristics, and low surface roughness is generally preferred. This study investigated the effects of several nanofluids (CuO, Al2O3, graphene, and multi-walled carbon nanotubes) on average surface roughness. Fig. 8 illustrates the measured surface roughness with varying nanoparticle concentrations (0.2 wt. %, 0.4 wt. %, 0.8 wt. %, and 1 wt.%). Graphene nanofluids provided the most significant reduction in surface roughness. Using the base cutting fluid resulted in a surface roughness of 1.18 μm; however, with 0.8 wt. % of graphene nanofluid, the surface roughness decreased to 0.78 μm, i.e. by 51.3 %. This is attributed to improved lubrication; nanoparticles on the metal surface formed a robust lubricant film, leading to better heat dispersion. The higher thermal conductivity and improved lubrication from increased graphene concentration reduced friction and heat generation. However, at 1 wt. % graphene concentration, the surface roughness increased to 0.8 μm compared to 0.8 wt.%, primarily because of nanoparticle agglomeration, which impaired the nanofluid’s performance. Higher cutting temperatures expedite the deterioration of the cutting tool, causing tool materials to soften and wear down, leading to reduced tool life, and can negatively affect surface finish. Extreme cutting temperatures can cause changes in the workpiece material microstructure because of heat generated in the cutting process, affecting properties such as hardness, tensile strength, and residual stresses. This study investigated how different nanofluids affect the average cutting temperature. Fig. 9 illustrates the measured cutting temperature with varying nanoparticle concentrations in nano cutting fluids (0.2 wt. %, 0.4 wt. %, 0.6 wt. %, 0.8 wt. %, and 1 wt. %). Graphene nanofluids provided the most significant reduction in cutting temperature. Using the base cutting fluid resulted in a cutting temperature of 48 °C; however, with
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