汽车油漆厚度的扫描电镜分析及其在同一认定中的应用初探

Scanning electron microscopic analysis of the thickness of automotive paint and preliminary study on its application in forensic identification

为探索汽车油漆截面厚度作为油漆物证同一认定的可行性,收集了13辆车不同部位的30个油漆样品,用液氮急速冷冻断裂后用离子研磨仪进行研磨,再用扫描电镜(SEM)对油漆各层厚度进行测量,并用SPSS软件对测量结果进行主成分分析。结果表明,离子研磨处理后样品的测量稳定性更好,同一辆车不同部位油漆各层厚度通常有较大差别。根据不同车辆同一部位油漆各层厚度的分析能够实现不同样品的区分。

In order to explore the feasibility of cross-sectional thickness measurement result of automotive paint as an evidence for forensic identification,30 paint samples from different positions of 13 vehicles were collected,and treated by ion milling after liquid nitrogen fracturing.The thickness of each layer of paint were measured by using a scanning electron microscope,and then principal components analysis of the measurement results were carried out in SPSS software.The result showed that the stability of thickness measurement was better after ion milling.There was quite a difference in the thickness of each layer between the paint samples from different positions of the same car.Different paint samples could be distinguished according to the analysis of the thickness of each layer of paint from the same position of different vehicles.