## 5 Conclusions  
This study systematically investigated the effects of various environmentally friendly dielectric materials on the rock fragmentation performance and discharge characteristics of metallic wire explosions, compared to those of conventional tap water as the dielectric. Based on experimental data and mechanism analysis, the main conclusions are as follows. 1. Dielectric materials significantly influence rock fragmentation efficiency and crack morphology. Compared to the tap water control group, all environmentally friendly dielectric materials, except for the CO\({}_{2}\)-dissolved liquid, outperformed the control in reducing the number of discharge cycles, increasing crack quantity and width, and enhancing rock fragmentation efficiency. Among these, ferric oxide and copper oxide suspensions exhibited the most remarkable fragmentation effects, achieving extensive crack penetration and debris spalling with fewer discharge cycles. This highlights the effectiveness of using oxidizing agents to strengthen the shock wave mechanism. 2. Diverse mechanisms influence energy distribution and transfer modes. Experimental results indicate that different dielectric materials enhance rock fragmentation performance through distinct mechanisms. Oxide-based dielectrics sustain energy release via thermochemical reactions, thereby enhancing the intensity and persistence of shock waves. High-conductivity salt solutions (potassium chloride and sodium chloride) improve energy deposition rates and shorten discharge durations, resulting in more focused and powerful shock waves. Reductant suspensions generate stronger secondary shock waves, which enhance crack propagation depth. Although CO\({}_{2}\)-dissolved liquids increase energy deposition efficiency, bubble pulsation and dissipation lead to shock wave attenuation during transmission, which hinders overall fragmentation performance. 3. Energy deposition efficiency and rock fragmentation performance exhibit a nonlinear relationship. While increasing dielectric conductivity or prolonging discharge duration can improve energy deposition efficiency, this does not necessarily translate to better rock fragmentation performance. For instance, CO\({}_{2}\)-dissolved liquids demonstrate higher deposition efficiency but require more discharge cycles to produce significant cracks. This indicates that the fragmentation process depends not only on energy input but also on the mode of energy release, the composition of the dielectric, and bubble dynamics during the process. 4. Engineering significance and application prospects: The findings of this study provide valuable references for achieving precision, customization, and eco-friendly applications of electrical explosive rock fragmentation technology in engineering practice. Selecting the appropriate dielectric materials can enhance fragmentation efficiency while controlling crack distribution and debris characteristics, thereby meeting the demands of different geological conditions and engineering requirements. Compared to traditional explosive methods, electrical explosion technology, through dielectric regulation, reduces environmental pollution and safety risks, making it more suitable for sustainable development and utilization in underground engineering, urban tunnel construction, and environmentally sensitive areas. [PERSON] was responsible for experimental design and manuscript writing; [PERSON] was in charge of optimizing experimental procedures and interpreting experimental data; [PERSON] conducted the literature review; [PERSON] and [PERSON] handled the processing of experimental data; [PERSON] managed the project. All authors have read and agreed to the published version of the manuscript. The project was funded by China University of Geosciences (Beijing). The funded project is the Adaptability Study of High-Voltage Pulsed Impact Crushing and Demolition Technology, with the project number 2-9-2023-026. Not applicable. The data presented in this study are available on request from the corresponding author.