A comprehensive review of vapour deposited coatings for cutting tools: properties and recent advances

The increasing demand for cost-efficient, high-quality machined products has led to a requirement for cutting tools that are able to provide a long tool life even when operating under extreme cutting conditions. Hard thin-film coatings deposited on tool substrates have been at the forefront of dealing with such demands. Such coatings provide cutting tools with properties like increased hardness, wear resistance, oxidation resistance, resistance to thermo-mechanical shocks, lower friction coefficient, etc. Vapour deposition techniques are widely used to deposit these thin films. Any variation in process parameters during deposition affects the properties of a coating and hence is a crucial factor to be considered. This review paper discusses some of the commercially used deposition methods, their effects on the crystal morphology, and the thermal and mechanical properties obtained in these coatings. Finally, this paper will also cover some of the recent advancements in hybrid coating technology, nanostructured coatings, and the prospects of sustainable machining.