A Comprehensive Review on Photochemical Machining of Metallic Materials

Photochemical Machining (PCM) is an established manufacturing process designed for the precision processing of metallic materials without inducing mechanical or thermal stress. This review provides an in-depth survey of the PCM process, beginning with the fundamentals of photoresist masking and the selective chemical etching of metals. It examines the material properties, like grain structure and surface conditions, that influence etchant performance and material removal rates. The selection and application of various etchants for different metals are detailed with a focus on optimizing chemical interactions to attain dimensional accuracy and uniformity. The review also addresses the economic feasibility and scalability of PCM, highlighting the influence of process factors, including etching time, etchant concentration and etchant temperature on output quality and process consistency. The review further addresses the surface integrity of the machined surface from various aspects. Recent advancements in combining PCM with other assisted processes to enhance productivity and reduce environmental impact are also discussed. Furthermore, strategies for multi-objective optimization are presented to balance competing goals such as cost, precision and production speed. The paper concludes by outlining the current challenges in PCM, including waste management, process standardization and material limitations, while suggesting future research directions aimed at sustainable automated and high-efficiency PCM systems.