Environment friendly milling of Inconel-625

Abstract

Inconel 625, having wide industrial applications, exhibits poor machinability because of rapid work hardening and poor thermal conductivity. Therefore, cutting fluids are utilised to remove heat and provide lubrication in the cutting zone, but their application poses serious environmental and health hazards, calling to minimise their use. Multi-walled carbon nanotube (NMQL) technique provides an effective alternative to flooded cooling-machining of Inconel and stainless steel. Current study evaluates performance of NMQL in terms of tool wear and surface finish during face milling of Inconel 625. To enhance thermal conductivity of MQL, soluble multiwalled carbon nanotubes (1% wt.) were mixed in vegetable oil. Cutting parameters were optimised to minimise tool wear and surface roughness and validation tests were also conducted under flooded and dry conditions to compare their performance with NMQL machining. Performance of cutting tool during NMQL machining was found to be 15.56% and 3.45% better than dry and flooded machining respectively, on the basis of tool wear (VB), and was 14.06% and 59.02% improved over flooded and dry machining respectively, in terms of surface roughness (Ra).