Abstract:

Objective In order to determine the cause of fire, laser Raman spectroscopy (RMS) is applied to characterize the crystal structure of the carbon during graphitization to explore the technical basis of electrical short circuit. Method The carbonized residues on copper molten marks caused by fire were examined with RMS. With the ratio(R) of two Raman characteristics peaks of carbon marks, the graphitization degrees of carbonization spot on the melten trace surfaces in different short circuits were calculated. Results It was found that the amorphous carbon content is different between electric and fire molten marks. The primary molten mark shows the lowest R value, while the secondary molten mark and fire molten mark shows higher one. Conclusion Based on the result, a method for discriminating molten marks is established, which can provide pivotal evidence for fire investigation.

Key words: copper wire, molten mark, laser Raman micro-spectroscopy, carbon residue

摘要：

目的 为了判定火灾发生的原因，依据激光拉曼光谱（RMS）能够反映出经过不同高温热处理炭材料的石墨化程度，以此来探索电气短路判定的技术依据。方法 利用显微共聚焦激光拉曼光谱仪对火灾中不同环境下生成的铜导线短路熔痕表面碳痕斑进行检测分析，利用碳痕斑两个拉曼特征位移峰的比值，计算不同短路熔痕表面碳化斑的石墨化度。结果 铜导线的一次短路、二次短路和火烧熔痕上残留碳斑石墨化度不同，一次短路熔珠碳痕的石墨化度R值最小，火烧熔痕的石墨化度R值最大。结论 该研究建立了显微激光拉曼光谱法无损检测分析铜导线短路熔痕的新方法。

关键词: 铜导线, 熔痕, 激光拉曼光谱, 碳残留物