A comparative study on the high temperature dry sliding wear behavior of TiN and AlTiN/TiSiN coatings fabricated by PVD technique

Purpose: This study aims to investigate the high-temperature wear behavior of the TiN- and AlTiN/TiSiN-coated WC materials. Design/methodology/approach: The coating process was carried out using the physical vapor deposition (PVD) method. Wear tests were performed by a ball-on-disc wear device with a high-temperature wear module. In microstructural investigation of the materials, it was benefited from traditional characterization methods such as, SEM, EDX analysis and microhardness measurement. Findings: The best wear performance was obtained with AlTiN/TiSiN-coated WC materials at all loads and temperatures, followed by TiN-coated and uncoated WC samples. An important wear was not observed on the samples tested at room temperature tests. It was found that the temperature increase is an effective parameter on the decrease of the wear resistance of the samples. In addition, it was seen that the increasing load and temperature change the wear mechanism on the uncoated WC sample. The wear mechanisms observed at high temperatures were delamination and oxidation for the WC, fatigue for AlTiN/TiSiN-coated WC and micro-scratch and micro-spalling for TiN-coated WC. Originality/value: The results of the experimental studies demonstrated that hard coatings improving wear resistance of WC. © 2019, Emerald Publishing Limited