OBRABOTKAMETALLOV technology Vol. 27 No. 2 2025 roughness (SR), and the integrity of the surface layer. Based on the analysis, the most effective SMAs machining methods were identified [28]. The optimization process of electrical discharge machining (EDM) for a high-temperature high-entropy shape memory alloy (HT-HE-SMA) with a composition of 35Ni-35Ti-15Zr-10Cu-5Sn using a copper electrode is considered. It is emphasized that EDM is an effective method for machining complex-geometry parts from difficult-to-machine materials, and optimizing EDM process parameters can significantly improve the productivity and quality of the machined surface. The relationship between the input EDM process parameters — discharge current (Ip), pulse-on time (Ton), and pulse-off time (Toff) — and the output parameters, such as material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR), was investigated. Response surface methodology (RSM) using a central composite design (CCD) was applied to evaluate the influence of machining parameters, and experimental data collection was performed using Minitab 19 software. Based on analysis of variance (ANOVA) at a significance level of 5 %, the most significant factors were determined, and the adequacy of the second-order regression models was evaluated. It was found that discharge current, pulse-on time, and pulse-off time have a significant effect on MRR, TWR, and Ra. The high accuracy of the developed mathematical models was confirmed, as evidenced by the high coefficients of determination (R²), reaching 97.82% for MRR, 99.53% for SR, and 95.36% for TWR [29]. The optimization of EDM parameters to achieve maximum MRR for NiTi, NiCu, and BeCu alloys was performed. Due to the difficulty of processing these advanced materials using conventional methods, EDM is considered an effective alternative. It is emphasized that the stability of the EDM process is a complex challenge due to the influence of numerous factors. This study investigates the optimization of EDM parameters by analyzing the current and voltage in the inter-electrode gap, combined with the control of pulse-on time, pulse-off time, and workpiece conductivity. A Taguchi orthogonal array was used for design of experiments (DoE), and Taguchi’s S/N ratio and ANOVA were used to determine the most significant factors affecting MRR. The results of the study demonstrate that EDM performance is largely dependent on the control of current and voltage in the gap, as well as pulse-on and pulse-off time [30]. The surface roughness (SR) and surface crack length (SCL) transformation in the EDM of electrolytic oxygen-free copper were evaluated using different processing modes. The influence of cryogenic treatment of the workpiece on EDM process parameters was investigated, including workpiece electrical conductivity, pulse-on time, pulse-off time, gap voltage, and gap current. The experiments were designed using a Taguchi L18 orthogonal array and subjected to statistical analysis. The results showed that gap voltage, pulse-on time, and pulse-off time have the greatest influence on SR, while the interaction of workpiece conductivity with gap current, pulse-on time, and gap voltage affects the surface crack length. It was found that the surface cracks length initially decreases with increasing conductivity and then begins to increase. A decrease in gap current leads to an increase in crack length, while an increase in gap voltage promotes a decrease in crack length. Machine learning models applied for regression analysis demonstrated high accuracy in predicting SCL and SR parameters, achieving a coefficient of determination (R²) exceeding 0.90 [31]. Tool wear rate (TWR) was minimized by optimizing the EDM parameters that influence the accuracy and cost-effectiveness of the process. Electrolytic copper was used as the electrode when machining NiTi, NiCu, and BeCu alloy workpieces. A Taguchi L18 orthogonal array was used to analyze the influence of various factors on TWR. The factors considered were: workpiece conductivity, gap voltage and current, pulse-on time, and pulse-off time. ANOVA in combination with Taguchi S/N ratio analysis revealed that workpiece material conductivity, pulse-on time, and gap current have the greatest influence on TWR. Based on the results, a set of optimal parameters was determined, allowing for reduced tool wear and improved EDM productivity [32]. Another study investigated the effect of cryogenic treatment and an external magnetic field on the EDM of beryllium bronze (BeCu). Experiments were conducted using different values of gap current, magnetic field strength, and pulse-on time, as well as electrolytic copper electrodes. The highest MRR of 11.807 mm³/min was achieved when machining cryogenically treated BeCu workpieces with untreated copper electrodes. Among the parameters studied, only the gap current had a significant influence on MRR,
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