Surface Integrity Enhancement of Inconel 718 in Dry Turning using Novel Soft Metallic Coated Lubricants

Abstract

Inconel 718 is a critical component in many sectors such as aerospace and nuclear due to its outstanding properties. As in these sectors parts are exposed to intense environments, any failure in the system can be calamitous. Thus, there are strict requirements for manufacturing precision and quality enforcement. However, poor machinability of Inconel 718 parts has caused ongoing challenges for both researchers and industry. The difficulties arise from the poor surface integrity of the machined parts due to its high strength at elevated temperatures, susceptibility to work-hardening, presence of hard carbides, low thermal conductivity, and built-up edge formation during machining. These characteristics make conventional machining methods less effective, necessitating innovative approaches. This study introduces an innovative solution to tackle this issue —a new in-situ coating method for depositing novel lubricating materials on the tool. Comprehensive machining tests and surface integrity analyses have been performed. The results show substantial improvements, including a significant prolongation in tool life, improved surface quality, and less machining-induced microstructural alteration. The success of using novel lubricious coatings in conjunction with the new in-situ method promises improved Inconel 718 machining as it resulted in exceptional tool performance and surface finishes that meet the tight standards of industry.