Doping Strategies for TiAlN-Based Cutting Tool Coatings: Progress and Perspectives

The continuous technological evolution of industry has intensified the role of machining processes, directly influencing product quality and industrial demands. Research in this field has long focused on friction during machining and the benefits of coatings in reducing energy consumption, improving workpiece quality, and extending tool life. Coated tools have been developed to overcome critical challenges, including thermal stability, corrosion resistance at elevated temperatures, and wear resistance under high speed machining. To meet these requirements, coating technologies have advanced, with methods such as CVD, PVD, and hybrid deposition gaining prominence. However, systematic evaluations of the performance evolution of TiAlN-based coatings doped with additional elements still require some attention from researchers. This review addresses that gap by examining the development of TiAlN coatings doped with elements like Mo, Si, Y, Ta, and Cr, as well as their combinations. It also discusses deposition techniques, thin film technologies, and their influence on coating performance. Finally, the paper outlines current trends, future research opportunities, and open challenges, providing insights relevant to both academy and industry.