Parametric optimization in electrochemical micromachining process of beryllium copper using cryogenically treated electrodes

Electrochemical Micromachining (ECMM) is an advanced non-conventional machining process used for producing precise micro-features without thermal damage or residual stresses. Beryllium Copper C17200 is widely used in aerospace, electronics, biomedical, and precision engineering industries for manufacturing components with micro-holes because of its robust strength, adequate electrical conductivity, and wear resistance. In this study, ECMM of Beryllium Copper C17200 was carried out using a cryogenically treated copper tool electrode and sodium chloride electrolyte to evaluate the effects of feed rate (FR), electrolyte concentration (EC), and machining standard voltage (AV) on surface roughness (Ra) and Material Removal Rate (MRR). Taguchi orthogonal array and ANOVA techniques were used for optimization and analysis of process parameters. The maximum MRR of 7.2 µm3/min was achieved at 21 V, 23 g/L electrolyte concentration, and 1 µm/s feed rate, while the minimum surface roughness of 0.612 µm was obtained at 19 V, 22 g/L, and 0.7 µm/s. The optimized ECMM parameters were identified within the range of 21 V, 23 g/L, and 0.8–1 µm/s. The ANOVA models showed high significance and accuracy with R2 values of 99.5% for MRR and 95.93% for surface roughness. The novelty of this work lies in the successful machining of BeCu micro-holes using ECMM without recast layer formation and with acceptable machining accuracy.