Impacts of Wear and Geometry Response of the Cutting Tool on Machinability of Super Austenitic Stainless Steel

Abstract

This paper presents a study of tool wear and geometry response when machinability tests were applied under milling operations on the Super Austenitic Stainless Steel alloy AL-6XN. Eight milling trials were executed under two cutting speeds, two feed rates, and two depths of cuts. Cutting edge profile measurements were performed to reveal response of cutting edge geometry to the cutting parameters and wear. A scanning electron microscope (SEM) was used to inspect the cutting edges. Results showed the presence of various types of wear such as adhesion wear and abrasion wear on the tool rake and flank faces. Adhesion wear represents the formation of the built-up edge, crater wear, and chipping, whereas abrasion wear represents flank wear. The commonly formed wear was crater wear. Therefore, the optimum tool life among the executed cutting trails was identified according to minimum length and depth of the crater wear. The profile measurements showed the formation of new geometries for the worn cutting edges due to adhesion and abrasion wear and the cutting parameters. The formation of the built-up edge was observed on the rake face of the cutting tool. The microstructure of the built-up edge was investigated using SEM. The built-up edge was found to have the austenite shear lamellar structure which is identical to the formed shear lamellae of the produced chip.