Surface texturing through photochemical machining for enhanced tribological performance: a review

Photochemical machining (PCM) is a precise, non-traditional manufacturing process used for surface texturing to enhance tribological performance, particularly in reducing friction and wear. This review discusses PCM's mechanism, advantages, and applications, emphasizing its role in lubrication efficiency, load-bearing capacity, and wear resistance. Various texturing techniques are compared, highlighting PCM's benefits over conventional methods due to its stress-free processing, high precision, and cost-effectiveness. The study examines key tribological parameters such as texture geometry, aspect ratio, and density, alongside the effects of etching conditions, including etchant composition, concentration, temperature, and processing time. The advantages of PCM, such as its ability to produce burr-free and complex microstructures, are analyzed, along with its limitations, including undercut, depth control challenges, and environmental concerns. Characterization techniques used to evaluate PCM textured surfaces in terms of tribological, physical, and mechanical properties are explored, confirming the method's effectiveness in improving lubrication, wear resistance, and material integrity. Research trends indicate a shift towards hybrid etching techniques, artificial intelligence driven predictive modelling, and sustainable etchant solutions to further refine PCM's capabilities. Future research should focus on minimizing isotropic etching, developing bio-inspired textures, and integrating real-time process simulations to enhance precision and efficiency. By addressing these challenges, PCM can be optimized for applications in tribology, biomedical engineering, microelectromechanical systems, energy systems, and aerospace, reinforcing its potential as a scalable and sustainable texturing method.