Life cycle assessment of drilling Inconel 718 using cryogenic cutting fluids while considering sustainability parameters

This novel study compares the drilling of Inconel 718 using two cryogenic cutting environments i.e., liquid carbon dioxide (LCO2) and liquid nitrogen (LN2) based on parameters like tool wear, power consumption, and surface roughness; and Life Cycle Assessment (LCA) results at three cutting speeds. As compared to LN2, 25-300% more holes were drilled using LCO2 due to restricted growth of wear mechanisms like chipping and abrasion. Overall, 14%, 19%, and 11% decrease in thrust force, power consumption, and surface roughness, respectively, are found with LCO2 as compared to LN2. Additionally, LCA is carried out using ReCiPe 2016 midpoint (H) method to evaluate the impacts on the environment, human health, and depletion of natural resources. Although improved machining performance with lower power consumption is found with LCO2, it has higher impacts on ecology across 17 of the 18 impact categories of the LCA.