Machining characteristics and process optimization of CFRP using internally supplied electrolyte ECDM

This study employs electrochemical discharge machining (ECDM) with internally supplied electrolyte to address issues such as fiber tearing commonly encountered in conventional machining of CFRP. The study on the material removal mechanism reveals that the machining of CFRP involves localized thermal erosion and brittle fracture of carbon fibers, as well as vaporization and carbonization of the epoxy resin. To enhance ECDM quality, single-factor experiments were first conducted to investigate parameter effects on material removal rate (MRR) and overcut (OC), followed by parameter optimization using an L9 (3 4 ) orthogonal array design with voltage, feed rate, duty cycle and electrolyte concentration as control parameters, where MRR and OC served as primary optimization targets to obtain single-objective optimal combinations. Grey relational analysis subsequently determined the multi-objective optimal parameter set for both metrics. Results show the optimal multi-objective parameters were: 40V, 3μm/s feed rate (FR), 80% duty cycle (DF), and 30% electrolyte concentration, which effectively improved both machining efficiency and quality for CFRP.