Developments in electrochemical discharge machining: A review on electrochemical discharge machining, process variants and their hybrid methods

•A comprehensive review on these recent developments in ECDM process, its process variants and their triplex hybrid methods.•Machined features with its complexity and accuracy level have been also presented.•Information regarding the materials that can machine has been also presented.•Research opportunities.

Electrochemical discharge machining (ECDM) is a hybrid non-conventional machining process, used to machine electrically conductive and non-conductive materials. It is a preferred process to fabricate micro scale features like micro holes, micro channels, microgrooves and 3-dimensional intricate shapes on variety of materials. In order to improve the efficacy of ECDM process, certain technical augmentations are provided with basic configuration of ECDM. These augmentations result in developments of ECDM process variants. Further, research community has developed ECDM based triplex hybrid methods for further process enrichment. This review article presents a comprehensive review of these recent developments in ECDM process, its variants and their triplex hybrid methods. The future research possibilities are identified and presented as research potentials.