Comparative analysis of dry, flood, MQL and cryogenic CO2 techniques during the machining of 15-5-PH SS alloy

The Precipitation Hardening (PH) Stainless Steel (SS) is considered as a promising alternative for aerospace and marine sectors owing to its good mechanical properties with high corrosion resistance. But the lower thermal conductivity and the presence of precipitates lower its machinability in terms of rapid tool wear. In this context, this study aims to analyze the dry, flood, MQL (Minimum Quantity Lubrication), and cryogenic machining with LCO2 in terms of tool wear for the turning tests of 15-5 PH SS. Apart from progressive flank wear, the machining performance of different cutting fluid strategies is compared by analyzing the crater wear, progressive power consumption, and surface roughness, microhardness, and microstructure of machined surface and chip. The performance of sustainable cryogenic machining is found superior in terms of lower tool wear, power consumption, subsurface microhardness. The relatively finer grain size and helical chip with smaller diameter are produced in the cryogenic machining while the better surface finish is observed for the flood machining in contrast to other cutting fluid strategies.