Tribological phenomena and tool wear mechanisms during machining of hard-to-cut TiAl6V4 aerospace alloy have been investigated in detail. Since cutting tool wear is directly affected by tribological phenomena occurring between the surfaces of the workpiece and the cutting tool, the performance of the cutting tool is strongly associated with the conditions of the machining process. The present work shows the effect of different machining conditions on the tribological and wear performance of TiB₂-coated cutting tools compared to uncoated carbide tools. FEM modeling of the temperature profile on the friction surface was performed for wet machining conditions under varying cutting parameters. Comprehensive characterization of the TiB₂ coated vs. uncoated cutting tool wear performance was made using optical 3D imaging, SEM/EDX and XPS methods respectively. The results obtained were linked to the FEM modeling. The studies carried out show that during machining of the TiAl6V4 alloy, the efficiency of the TiB₂ coating application for carbide cutting tools strongly depends on cutting conditions. The TiB₂ coating is very efficient under roughing at low speeds (with strong buildup edge formation). In contrast, it shows similar wear performance to the uncoated tool under finishing operations at higher cutting speeds when cratering wear predominates.

Tool wear is an important machinability criterion. For the sake of reduction of the total machining cost; this study demonstrates the wear and tribological performance of four ceramic tools in dry high speed turning of Ni-Co-Cr precipitation hardenable superalloy (Inconel 100). Wear of the tool materials and the structural and phase transformations at the tool/chip interface were investigated. Results obtained reveal that SiAlON ceramic outperformed other ceramic tool materials at different cutting speeds due to the formation large amount of mullite tribo-films on the tool face, which serve as a thermal barrier layer. Alumina ceramic with addition of ZrO₂ can be recommended for machining Inconel 100 at speeds above 150 m/min due its ability to form thermal barrier ZrO₂tribo-films, which decrease of coefficient of friction at the tool chip/interface. Mixed alumina and alumina matrix reinforced with SiC_w were found to be not suitable for machining age-hardened Inconel 100 superalloy.