Investigation on the morphology of the machined surface in end milling of aerospace AL6061-T6 for novel uses of SiO₂ nanolubrication system

Aluminium 6061-T6 alloy is commonly used in the aircraft and automotive industries for its superior mechanical properties. To improve machining performance such as tool life and workpiece surface finish, lubricant oil is normally introduced into the cutting zone during the machining process. However, at higher temperature and pressure in heavy industry machining, the ordinary oil lubricant has no function as it is usually evaporated. Introducing SiO ₂ nanolubricant in the cutting zone could withstand this severe conditions and the rolling action of billions of nanoparticles in the tool chip interface produces much less friction and thermal deformation leading to superior surface quality. Using nanolubrication in machining could also minimize the consumption of lubrication oil; consequently, less pollution will be caused. To ensure workpiece surface quality, a morphological analysis of AL6061-T6 after machining with SiO₂ nanolubricant is investigated at different nanolubricant concentration using Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray (XRD) machines. From the results and analysis, the increment of nanolubricant concentration at 0.2% would increase the growth of thin protective film on machined surfaces due to the breaking process from the rolling action of billions of nanoparticle between the tool-chip interfaces. These formations of the thin film on the machined surface could improve the machining performance by reducing the cutting force, reduce the cutting temperature and improves the surface quality.