Process Parameters and Machining Performance in Wire Electric Discharge Machining: A Review

Abstract

Wire Electrical Discharge Machining (WEDM) is widely regarded as a sophisticated non-traditional machining technique utilised for processing difficult-to-machine materials such as titanium alloys and high-strength engineering alloys. Due to its ability to produce intricate geometries with high-dimensional accuracy and excellent surface quality, WEDM has attracted significant interest in contemporary manufacturing sectors. This study provides a comprehensive review of the existing literature, with a particular focus on the optimisation of WEDM process parameters and their impact on machining performance. The key response variables examined in prior research include material removal rate (MRR), surface roughness (SR), dimensional accuracy, and kerf width. Critical process parameters such as pulse-on time, pulse-off time, peak current, wire feed rate, and servo voltage have been identified as major factors influencing machining efficiency and output quality. To achieve optimal performance, various optimisation methodologies, including the Taguchi method, Response Surface Methodology (RSM), Grey Relational Analysis (GRA), fuzzy logic-based techniques, and machine learning approaches, have been extensively applied to determine the most suitable machining conditions. Furthermore, the selection of electrode material and coating has been shown to influence machining stability and surface integrity, with zinc-coated brass wire electrodes demonstrating improved flushing efficiency and enhanced performance. Recent advancements in hybrid optimisation strategies and artificial intelligence-based models have further enhanced prediction accuracy and facilitated effective multi-objective optimisation. Overall, the review highlights that systematic optimisation of process parameters, combined with advanced modelling and intelligent optimisation techniques, is essential for improving machining efficiency, surface quality, and dimensional accuracy in WEDM, particularly when machining difficult materials such as titanium alloys.