Spark eroding machining performance, surface textures and optimization strategies for ceramic composites: a review

In recent years, notable advancements have been achieved in the field of material science, particularly in metallurgy and ceramic materials. Electrical discharge machining (EDM) has become an indispensable non-conventional machining process, especially suited for intricate shaping of tough materials like ceramics and composites. This comprehensive review delves into the core mechanisms of EDM, focusing on the interplay of thermal energy and electrical discharges. The influence of dielectric fluids and cutting-edge electrode materials is highlighted for their significant role in enhancing machining performance and material removal efficiency. Various EDM techniques, including dry EDM, powder-mixed EDM, micro-EDM, and wire EDM, are explored with a particular focus on their effects on precision, surface quality, and overall material integrity. In particular, the machining of advanced ceramic composites, such as Si3N4-TiN and MoSi2-SiC, is emphasized, where optimizing process parameters becomes crucial to overcoming machining challenges. Key aspects like surface roughness, the formation of recast layers, and alterations in microstructure are scrutinized for their impact on the durability and properties of the final product. The review also sheds light on advanced optimization strategies, including Artificial Neural Networks (ANN), fuzzy Multi-Objective Optimization (MO), genetic algorithms, and hybrid methods like Particle Swarm Optimization (PSO) and Teaching-Learning-Based Optimization (TLBO). These tools are essential for boosting EDM performance, especially in applications demanding high precision. The paper ends with some observations about the expanding use of EDM in biomedical applications, especially in the manufacturing of implants and other medical devices.