An experimental investigations on effects of cooling/lubrication conditions in micro milling of additively manufactured Inconel 718

The demand for additive manufacturing (AM) technology is recently increased in the aerospace, biomedical, and automobile sectors due to the capability of producing complex components with zero tolerance. However, the small or precise part manufactured by AM process needs post-processing such as machining, polishing, etc. because of the poor surface quality characteristics. Therefore, in this paper, the micro-milling was performed on additively manufactured Inconel-718 alloy under different sustainable cooling conditions. The tool wear, surface roughness, and burr generated during micro-milling experiments were investigated under the effect of air, minimum quantity lubrication (MQL), and flood cooling conditions. The results demonstrated that the MQL conditions provide the proper cooling and lubrication effect, and this results in improved tool life (which is almost 45% higher compared to dry conditions. MQL also improved the product quality in terms of surface roughness (almost 65% less surface roughness). Other machining characteristics, such as burr width and cutting forces, were also improved in MQL and flood environments. However, it was noticed that milling with a chilled air environment has not given any significant improvement in terms of machining characteristics.