Performance of composite coating on cutting tools: coating technologies, performance optimization, and their characterization: a review

Abstract

Cutting tool development has drawn a lot of attention for the machining of tough to machine materials in the past decade. Conventional cutting tools (such as high-speed steel (HSS), cemented carbide, cubic boron nitride (CBN), etc., have been widely used in the cutting of difficult to machine materials. These cutting tools have limited scope of application due to their wearing during machining, their design, and manufacturing restrictions. To enhance machinability, cutting tools are coated with different nanostructured coating. The indicative properties of such hard coatings are adhesiveness to the substrate, great microhardness, and toughness. Present work reviews the impact of various hard coating (based on Ti, AlN, SiN, and their combinations), forces and surface roughness, and cutting factors (as speed and feed rate) are reviewed. Electrical discharge machining (EDM) is widely used for machining of difficult to machine materials on a large scale, which would be overpriced and impractical to obtain from conventional machining. The cost contribution of tool in the total operation cost of EDM is maximum. Major challenge in the EDM tool is tool wear. Hence, hard coating on the EDM electrode can also be applied in order to restrict the tool wear rate of the EDM electrode, increase the workpiece surface finish and reducing the machining time. In this paper, a coated EDM electrode used for the machining of hard material is also reviewed.