Influence of the pulse shape on the EDM performance of Si3N4-TiN ceramic composite

This paper describes the influence of the EDM discharge pulse shape on the machining performances and material removal mechanisms of Si₃N₄-TiN. Dramatic differences of material removal, ranging from classical melting to chemical decomposition, are observed by applying different pulse shapes such as the iso-energetic or relaxation type discharge pulses. It not just leads to the change of surface texture and machining performances, but also has influences on the ceramic properties. An EDM strategy is developed for the production of ceramic components in Si₃N₄-TiN and validated through the fabrication of a high temperature mesoscopic gas turbine.