Hole quality improvement in CFRP/Ti6Al4V stacks using optimised flow rates for LCO$_2$ and MQL sustainable cooling/lubricationRodriguez, I. (Avtor) Arrazola, P. J. (Avtor) Cuesta, M. (Avtor) Pušavec, Franci (Avtor) CFRP/Ti stackscutting temperature▫$LCO_2$▫ assisted drillingsurface integrityoptimisationCarbon fibre reinforced polymer/titanium stacks (CFRP/Ti6Al4V) are employed in aeronautics due to their excellent weight-to-strength ratio and corrosion properties. However, these same material properties present challenges for hole making which cannot be solved using conventional water-based metalworking fluids (MWFs), as they cause degradation of the composite. Moreover, environmental and health concerns require exploration of alternative cooling/lubrication solutions. In this study, a controlled mixture of liquid carbon dioxide (LCO$_2$) and minimum quantity lubrication (MQL) was supplied through the drilling tool. The effect of varying LCO$_2$ and MQL flow rates was evaluated on cutting forces, temperatures, and several hole quality outputs. The optimal flow rates were then determined through multi-objective optimisation. The results show that the cooling/lubrication flow rate greatly affects the measured outputs, and that supplying LCO$_2$ + MQL with optimised flow rates helps achieve superior quality holes in CFRP, Ti6Al4V and CFRP/Ti6Al4V stacks.20242024-04-10 11:13:34Članek v reviji155658sl