Comparison of CrN and CrTiN Hard Coatings Developed on SiAlON Tool Inserts via Magnetron Sputtering Process

The present study comparatively examines the CrN and CrTiN hard coatings developed on SiAlON ceramic tool inserts via magnetron sputtering PVD process. Different characterization techniques investigated the properties of the deposited coating. Energy-dispersive x-ray spectroscopy (EDS) is utilized to validate the elemental composition of the coating present on the substrate. The analysis of phase composition was conducted through the utilization of x-ray diffraction (XRD), while the examination of surface morphology was carried out using field-emission scanning electron microscopy (FESEM). Hardness and adhesion strength between deposited coating and substrate were characterized by micro-indentation test. Comparison of hard turning performance of bare and coated cutting tool was made by performing turning tests. The machining forces, temperature of tool workpiece interface, wear of cutting tool, and surface roughness were all considered when analyzing the turning behavior. The findings showed that SiAlON cutting inserts coated with CrN and CrTiN coating had higher hardness, and adequate adhesion between coating layer and the substrate was achieved. The machining performance of CrTiN-coated SiAlON tool inserts was much better than the CrN-coated tool and uncoated SiAlON cutting insert. Moreover, it can be seen that while turning hardened steel, the coated inserts were worn through a combination of abrasion and adhesion wear mechanisms under certain cutting circumstances.

Automated summary

This study compares the CrN and CrTiN hard coatings developed on SiAlON ceramic tool inserts using magnetron sputtering PVD process. Different characterization techniques, such as EDS, XRD, and FESEM, were used to investigate the properties of the coatings. Micro-indentation test was conducted to characterize the hardness and adhesion strength. Turning tests were performed to compare the machining performance of coated and uncoated cutting tools. The findings show that SiAlON cutting inserts coated with CrN and CrTiN exhibit higher hardness and adequate adhesion, with better machining performance for CrTiN-coated inserts.