Research on surface roughness of high-speed milling 7075-T6 aluminum alloy using nanofluid/ultrasonic atomization minimal quantity lubrication system.

This study employed a self-developed nanofluid/ultrasonic atomization minimal quantity lubrication system. The use of ultrasonic cavitation can effectively improve the accumulation of nanofluids via van der Waals force bonding and enhance their efficiency. This system is a high-speed milling manufacturing innovation in lubrication technology. Two types of nanoparticles (multiwalled carbon nanotubes and MoS₂ nanoparticles) were used to facilitate the mixing of nanofluids and their lubrication in the high-speed milling of 7075-T6 aluminum alloy. The surface roughness of each group of experimental results was used as the characteristic index. The surface roughness obtained from the optimization of the experimental results was 0.51 μm, while the worst group, which was based on the original orthogonal table, had a surface roughness of 1.05 μm, demonstrating an improvement of 51.43% in the quality characteristics. Results of comparative experiments demonstrated that using a nanofluid mixed with multiwalled carbon nanotubes and MoS₂ nanoparticles exerted better effects on surface roughness, tool wear, and workpiece burrs than using only nanofluids with single nanoparticles. This finding can be attributed to the mixed nanofluid, which simultaneously possesses the good grinding capability of MoS₂ and the excellent heat transfer property of multiwalled carbon nanotubes.