Application of Microwave-Metal Discharge for Metallic Material Removal

Microwave irradiation at 2.45 GHz is considered a clean and economical energy source. Material processing using microwave energy has emerged as a potential solution for various applications. The discharge effect has gained immense popularity while exploring material processing in the past few decades. Microwave-induced discharges are currently utilized in several material processing applications such as pyrolysis, pollutant removal, material synthesis, sintering, etc. The present work investigates the physical aspects of microwave-metal discharge and emphasizes its ability to machine metal-based materials. This chapter briefly reviews the different theories proposed regarding the mechanism of microwave-metal discharge, its effects, potential applications, and the related challenges. The article also presents some results emerging from a few experimental investigations performed to understand the impact of microwave-metal discharges on the ablation characteristics of AISI 304 stainless steel in atmospheric air medium. The study compares the effect of microwave-metal discharge exposed to AISI 304 for the time durations of 30 s, 40 s, and 50 s. The irradiated and ablated areas formed by the discharge were evaluated at different time intervals. The article also suggests possible plasma confinement strategies to further improve the machining performance.