Growth of a hard, novel CVD multilayer coating: Ti(C,N) on (Ti,Al)N on TiN

Reviewartikel, 2025

A novel chemical vapor deposition (CVD) multilayer coating intended for cutting applications was designed to achieve high wear and heat resistance during metal machining. The coating consists of three layers: a TiCN layer deposited on top of a TiAlN layer, which was grown on a layer of TiN that was deposited onto a cemented carbide substrate. The detailed microstructure of the coating was examined using a combination of electron microscope techniques. Two pyramidal surface morphologies and textures were observed, which could be related to the substrate roughness. Two growth modes were found: epitaxial growth of 〈211〉 oriented TiCN on <211> oriented TiAlN on <211> oriented TiN, leading to tilted TiCN pyramids at the coating surface; and epitaxial growth of 〈111〉 TiCN on <111> TiAlN on <111> TiN, leading to symmetrical TiCN pyramids at the coating surface.