Tool Wear and Machinability Investigations of Al2O3-ZrO2 Ceramic Tool in Dry Turning of Inconel 718

ABSTRACT The high heat resistance of Inconel 718 poses challenges in the machining process. Smart machining factor adoption can improve its machinability. This study is focused on investigating the use of Al2O3-ZrO2 ceramic inserts in turning process of Inconel 718 to examine the impact varying machining settings on surface roughness, tool wear, and material removal rate. The turning process input variables used were feed rate (f), cutting speed (v), and depth of cut (d). The influence of each variable on surface roughness, tool wear, and material removal rate was analyzed using two-dimensional surface plots and the main effect plot. Scanning electron microscopy and energy-dispersive spectrographic examination were conducted to explore the various wear pattern mechanisms on the tool face. Analysis of variance was used to determine the percentage impact of all turning process variables on response variables. The quadratic mathematical model for surface roughness and material removal rate showed strong concordance with both experimental and predicted results. Abrasive marks were perceived on the tool face when experiments conducted at a high cutting speed (565.4 m/min), a minimal depth of cut (0.1 mm), and a low feed rate. The depth of cut was increased from 0.1 to 0.5 mm, and while keeping a constant cutting speed, the abrasive area increased. The presence of nickel, chromium, and iron proposes the adhesion of Inconel 718, leading to the formation of various oxide layers at high temperatures. As a consequence, built-up layers and a built-up edge are formed on the tool face. The study gives insight on the significance of Al2O3-ZrO2 ceramic inserts in improving the machinability of Inconel 718 and provides valuable insights into the wear mechanisms during the machining process.