Advances in nano-powder mixed electrical discharge machining (NPEDM): mechanisms, applications, and emerging Trends (2021–2025)

Abstract

In-situ Nano-Powder Mixed Electrical Discharge Machining (NPEDM) represents a revolutionary alteration of conventional EDM complemented with nano-scaled powder to effectively enhance material removal rate, reduce tool wear, and improve surface quality. This critical review covers the advances in NPEDM during the period from 2001 to up to 2025 to pinpoint the effect of various nano-powder types (e.g. Al₂O₃, SiC, CNTs, hydroxyapatite) and process parameters on the material removal rate and functional surface properties. This work differs from earlier reviews by a predictable categorization of past studies, identifying deficiencies in our current understanding of powder–dielectric interactions, and discussing the potential of developing industrial and biomedical applications. The challenges in powder agglomeration, control of recast layer and care of standardized operating parameters are summarized, while ranges of opportunities in the development of the process, such as AI-based optimization of process parameters and application of eco-friendly dielectric fluid, are explored. This study synthesizes two decades of research and offers a holistic view of NPEDM as a sustainable high precision machining technology with significant relevance towards industry.