Properties of (Cr,Al,Si)N-(DLC-Si) composite coatings deposited on a cutting ceramic substrate

The article discusses the specific features of the deposition of (Cr,Al,Si)N-(DLC-Si) composite coatings on the (Al2O3 + TiC) ceramic substrate and studies the performance properties of ceramic cutting tools with the above coatings. Three coating options were considered, including a (Cr,Al,Si)N transition layer and a DLC-Si wear-resistant layer with various options of Si content. The coating structure was investigated using scanning electron microscopy, transmission electron microscopy (TEM), and high-resolution TEM. The crystalline structures of the coatings were studied using the selected-area diffraction pattern. The studies substantiated the need for the application of a (Cr,Al,Si)N transition layer between a ceramic substrate and the DLC-Si coating, and the influence of the Si content on the coating properties was also considered. The cutting properties of tools with the DLC-Si coatings of various structures were studied during the turning of AISI 52100 (HRC 56-58) hardened steel. The studies also focused on the wear pattern of uncoated tools and tools with the studied coatings. The application of the (Cr,Al,Si)N-(DLC-Si) coating changes the wear pattern and can prolong the life of a ceramic cutting tool.