Performance evaluation of deep cryogenic processed carbide inserts during dry turning of Nimonic 90 aerospace grade alloy

Nickel based alloys are very difficult to machine under dry environment due to its low thermal conductivity and high chemical affinity. Generation of high temperature and friction during machining of nickel alloys results in extremely high tool wear. In order to improve the effectiveness of the cutting inserts under dry environment, deep cryogenic treatment of coated and uncoated carbide has been carried out. Comparison of the performance of the cryogenically treated and non-treated inserts has been conducted during the turning of Nimonic 90 alloy. The results demonstrated that the cryogenic treatment has improved scratch resistance of the cutting inserts. Appreciable reductions in flank wear over tool nose, cutting forces and chip tool contact length have also been noticed for the treated inserts.