Recent advances and challenges associated with thin film coatings of cutting tools: a critical review

ABSTRACT Metal cutting is a necessary operation in any production industry. Rapid production has become a necessity as a result of recent trends in high-speed machining and automation. The demand for more sophisticated and advanced cutting tools has significantly increased in recent years. The properties of alloy metals can be improved by applying a thin film to enhance or reduce specific properties based on product needs. The effect is being able to operate the tool at a higher cutting speed, feed rate, depth of cut, and longer tool life, with a dry machining possibility for the end-user when cutting tools are appropriately coated and performing as intended using thin films. Thin coatings improve cutting tool wear resistance, oxidation resistance, friction reduction, resistance to metal fatigue, as well as thermal shock resistance. On the other hand, thin film morphology and stability are crucial challenges in cutting tool applications as thin film morphology is heavily dependent on deposition techniques. As a result, based on the available studies, this article presents a critical review of deposition coating techniques, characterisation methods, and evaluation techniques in order to prevent excessive damage and improve the mechanical properties of cutting tools. The anticipated outcomes of this review can be used as a guide to help researchers understand various coating techniques and their effects on cutting tool properties.