Performance Evaluation of Sustainable C/L Strategies in Milling Carpenter® 20: Towards Green Manufacturing with Cryo + NF-MQL and Quenched Tool

Carpenter® 20, a Ni-Fe-Cr-based material, stands out for its exceptional corrosion resistance. However, its complex composition makes it difficult to machine due to rapid tool wear, high cutting temperature, and challenges in maintaining surface integrity. Optimizing machining strategies, particularly cooling and lubrication (C/L), is critical to ensure desired performance, surface finish, and extended tool life. Emerging C/L strategy, cryogenic (cryo) assisted nanofluid (NF) in minimum quantity lubrication (MQL) is gaining traction, which drastically enhances heat dissipation. Graphene (Gr) based nano particles (NPs) with high thermal conductivity, chemically inert, and low density were addedto the corn oil, which was used as an NF. This study focuses on milling of Carpenter® 20 with a quenched TiAlN-coated tool to assess the surface quality, tool wear, chip morphology, and residual stress with distinct cutting strategies (Dry, NF-MQL, and cryo + NF-MQL). The results showed that flank wear under cryo + NF-MQL condition was 0.163 mm after 2500 mm of cutting. Further, it reduces coating delamination, abrasion, and adhesion on both faces of the tool. The surface roughness was reduced by 46–48% (dry) and 9–12% (NF-MQL) in comparison to cryo + NF-MQL. Additionally, residual stress was analyzed on the machined face, which shows cryo + NF-MQL with a lower value of 336 MPa and 371 MPa with different cutting speeds.