Wear behaviour of deep cryogenically treated coated tool during end milling of XH67MBTHO

XH67MBTHO is a Ni-based superalloy which finds usage in high temperature applications of aero engines. However, attributed to some of their inherent properties like strain hardening and poor thermal conductivity, tool life characteristics are adversely affected during the machining operations. The use of conventional TiAlN coated tools can address the tool wear issues faced during machining of similar Ni-based alloys. However, severe coating delamination, and significant adhesion wear mechanisms could negatively influence the effectiveness of the tools at dry lubricating conditions. The current study investigates the influence of a sustainable manufacturing technique through DCT (Deep Cryogenic Treatment) and its impact on coated tool inserts to address the tool wear issues under dry machining conditions. The DCT aids in the formation of η (eta) phase carbides, β-phase densification etc. Hence, the tool substrate develops significant wear resistance and fracture toughness in withstanding the contact stress at the machining interface. Notch wear, micro-crack formations, and built-up layer generations were observed to be major wear mechanism, and for treated tool (TT) it was less severe. Furthermore, the maximum reduction in average flank wear widths for treated tool was observed to be 26%, while the cutting force and surface roughness values were found to be reduced by 27%, and 24% respectively compared to untreated tool (UTT).