Self-adaptive coated cutting tools: a critical review

The rapid development of advanced engineering materials has pushed cutting operations into regimes characterized by extreme thermomechanical loads, revealing the limitations of conventional coated tool systems. To address these operational challenges, self-adaptive coating technologies have been developed to enable real-time modulation of performance under dynamic machining conditions. These coatings exhibit autonomous structural and functional responses to harsh working environments, thereby preserving cutting performance across a wide range of conditions. This review provides a critical assessment of self-adaptive coated cutting tools, focusing on two principal categories: self-organizing and self-lubricating systems. The preparation methods, cutting conditions, and degradation mechanisms of self-adaptive coatings are summarized and discussed. The respective advantages and limitations of each coating type are evaluated to inform their practical application and guide further development. Finally, a summary and outlook are presented to highlight future research directions in the field of self-adaptive coated cutting tools.