The SiC reinforced z-pinned composites are becoming advantageous in the field of aerospace and defense sector due to their superior mechanical properties. The reinforcement of SiC particles makes them difficult to machine with conventional machining processes. In the present research investigation, the micro-slicing of SiC reinforced z-pinned composites has been attempted using wire electrochemical discharge machining (WECDM). WECDM is newly emerging technique which combines the process features of electrochemical machining (ECM) and wire electrical discharge machining (WEDM) processes. The experiments were planned using Taguchi’s methodology using L9 Orthogonal array to study the effect of various process parameters i.e. applied voltage, wire feed rate (WFR) and duty cycle on the output quality characteristics such as diametric overcut (DOC) and material removal rate (MRR). The grey relational analysis (GRA) methodology was implemented for multi-response optimization. The diametric overcut and material removal rate of machined samples at optimum parametric conditions of GRA method improves from 71.87 μm to 60.20 μm and 34.20 mg/min to 32.30 mg/min respectively. The morphology of micro-sliced sample using GRA method signifies better quality machined surface with minimization of micro-cracks and uniform cutting.