Abstract
Copper-clad aluminum wires have a high risk of electrical fire, and welding marks are easily affected by factors such as high temperature and fire water in the actual fire. To accurately identify the overcurrent fault, an electrical fault simulator was used in this study to simulate the overcurrent fault condition of a copper-clad aluminum at a current of 52.5–105 A. Then the microstructure characteristics such as metallographic structure, welding hole elements, and so on under different treatment methods were also analyzed using the metallographic microscope and SEM/EDS. The results of the study are summarized as follows: (1) under the method of natural cooling, the metallographic structure of the welding mark were mainly columnar crystals and dendritic crystals with a few holes in it. And we found that the maximum particle size and average particle size have a quadratic function relationship with the current value; (2) under the water-cooling method, the welding mark was mainly columnar crystals with a large number of holes in them. At a current of 75 A, the welding mark holes consisted of Al and Cu elements, while at the rest of the current value, they consisted of Al, Cu, and O elements; (3) when the temperature was raised to 450 °C, the welding trace has different elements at different currents. At the temperature of 650 °C, a large number of equiaxed crystals appeared in the welding trace, with a few holes in which at a current at 105 A only. Our study has provided a basis for the investigation of electrical fire accidents and the technical identification of the causes.
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Acknowledgements
This work was supported by the National Key R&D Plan (2021YFE0105000), National Key R&D Plan (2023YFC3009800), National Natural Science Foundation (52074213), Shaanxi Key R&D Plan (2021SF-472, 2022QCY-LL-70), Shaanxi Qin Chuangyuan "Scientists+Engineers" Team Construction (2023KXJ-052).
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WW contributed to Article ideas and experimental tests, and wrote the paper. XJ contributed to Further deeply discussed experimental ideas. FZ contributed to Completed the data testing. XZ contributed to Completed the data analysis. XG contributed to Improved analysis methods. DH contributed to Review and editing. LW contributed to Check the final version of the paper to be published.
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Wang, W., Ji, X., Zhang, F. et al. Study on the microstructure characteristics of melting marks in copper-clad aluminum wires under overcurrent faults. J Therm Anal Calorim 149, 345–357 (2024). https://doi.org/10.1007/s10973-023-12681-5
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DOI: https://doi.org/10.1007/s10973-023-12681-5