Experimental analysis of the substrate influence in tool life in slot milling of stainless steel

Abstract

Stainless steels are widely known as difficult-to-cut materials, especially under hard machining conditions pushing the solid carbide end mill up to its breakage. This study examines the influence of different tool substrates in conventional slot milling of AISI 316L at demanding cutting conditions to analyze the tool’s life. The employed tools are four-flute, 12 mm diameter end mills with identical geometries and TiAlN coatings, differing only in substrate material. Mean and peak cutting forces were recorded, with tool wear on the edge and flank face measured every two minutes. As machining progressed, both cutting forces and tool wear increased until tool failure, with tool life ranging from 8 to 15 minutes. The difference between the different substrates has been quantified showing that tool life can be improved by 50% with the right substrate. Finally, the composition of the substrate, as well as the microstructure, was analysed in a SEM being able this way to link this input with the wear and the breakage that occurred during the machining tests.