利用火灾痕迹物证综合实验台, 制备多股铜导线在不同过载电流作用下的残留物, 用数码相机和扫描电子显微镜观察和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、熔化以及炭化, 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, 利用数码相机和扫描电子显微镜观察和分析多股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。

The integrated experimental system of material evidence for fire trace was used to make residue of the more strands copper wire under different overcurrent.The surface morphologies of the wire were observed and analyzed by the digital camera and scanning electron microscope.The results indicated that with the increase of overcurrent the insulating cover from softening, bulge, ebullition, melting, carbonization to disengage with core wire. The surface oxidation of core wire becomed serious. The grooved processing nicks becomed no conspicuous, and the core wire surface presented metal melting flowed trace. Therefore, using digital camera and scanning electron microscope to observe and analyze the character of the surface morphology of the more strands copper wire can identify whether it is overloaded and the degree of overload.