Improvement of machinability in end milling of Nimonic C-263 by application of high pressure coolant

Abstract

This paper investigates the effect of machining environments, conventional wet, liquid nitrogen (LN2) and high pressure (HP) cooling on tool performance when machining nickel-based, Nimonic C-263, alloy with dual layer coated (TiN/TiAlN) carbide insert under different cutting speed and feed conditions. Tool life, tool failure modes, surface integrity and surface finish generated during end milling were recorded and analysed. Analysis of the test results shows that high pressure (50 bar) cooling gave the best result compared to other two machining environments in terms of tool life. Tool life improvement of as high as 133% was recorded under high pressure cooling compared to conventional wet. LN2 cooling gave worst results among all three cutting environments, due to increased thermal fluctuation during machining. Chipping was found to be the dominating tool failure mode in all the cases. Plastic deformation of the machined surface was evident with increase in tool wear.