Research on oxidation characteristics of electrical contact melted mark in short circuited fire

摘要

Electrical contact melted mark is a product of conductor to melt and deform when it fails during electrical contact. The short circuited fire is essentially caused by failure of electrical circuit at electrical contact to ignite surrounding combustible. It is extremely important to study the oxidation process of short circuited metal melted marks from the angle of electrical contact for improving the accuracy and scientificity of cause identification. This paper discusses the heating of electrical contact and high temperature oxidation of copper, analyzes and studies the element distribution at the surface and inside the primary short circuited melted marks and second short circuited melted marks. Melted mark samples with different type of electrical contact is prepared by stimulation experiment and structural feature parameters of samples, element content and element distribution map are obtained with scanning electron microscope, energy spectrometer and computer image processing software. In addition, after comparison and analysis of experimental results, SEM&EDS is used to qualitatively and quantitatively analyze the electrical contact melted mark in short-circuited fire.