铜导线过载残留物表面形貌分析

利用火灾痕迹物证综合实验台,制备铜导线在不同过载电流作用下的残留物,用数码相机、扫描电子显微镜观察、分析导线的表面形貌。结果表明：随着过载电流的增大,绝缘层逐渐变软、膨胀、起泡、炭化,并与芯线脱离;芯线表面氧化程度加重,沟槽状的加工划痕逐渐消失,并出现金属熔化流淌痕迹。因此,利用数码相机、扫描电子显微镜观察、分析铜导线表面的形貌特征,可以鉴别其是否过载以及过载的程度。

Surface Morphology on Overload Residue of Copper Wire

The integrated experimental system of material evidence for fire trace is used to obtain the residue of the copper wire under different overloaded current.The surface morphology of the wire was observed and analyzed by the digital camera and scanning electron microscope.The result indicates that with the increase of overloaded current,the insulating cover from softening,bulge,ebullition,charring to disengage with the core wire.The surface oxidation of core wire becomes serious.The grooved processing nicks become no conspicuous,and the core wire surface presents metal melting flowed trace.Therefore,using digital camera and scanning electron microscope to observe and analyze the character of the surface morphology of the copper wire can identify whether it is overloaded or not and the degree of the overload.