金属火灾熔痕的显微组织及物相成分的实验研究

The Microstructure and Phase Composition of Metal Melting Marks Caused by Different Fire

利用X-射线衍射(XRD)和3D图像处理软件(Image-pro)研究了四种不同火灾类型金属熔痕的显微组织、平均晶粒度、物相组成及其分布规律。结果表明:金属火灾熔痕主要由立方晶系的Cu2O和胞、枝状的Cu组成。在四种不同的起火方式下,金属熔痕的显微组织和成分有显著的差别:(1)一次短路的火灾熔痕平均晶粒度为3～5μm,其Cu2O含量最低;过载熔痕的平均晶粒度与一次短路的类似,但其Cu2O含量为30%左右;(2)二次短路熔痕中含有一定数量直径较大的微观空洞,平均晶粒度约为30μm;其Cu和Cu2O衍射峰出现展宽和辟裂,烧蚀程度最深;(3)火灾熔痕中粗大的Cu2O等轴晶衍射峰强度最大,且显微组织中几乎没有微观空洞存在。

Four different types of molten metal fire marks were studied through X-ray diffraction （XRD） and 3D image process- ing software （Image-pro）. As a result, the microstructure, average grain size, phase composition and its distribution was oh- tained. The results showed that on the surface of molten metal fire marks there mainly existed cubic crystal of Cu2 O, cellular crystals of Cu and columnar crystals of Cu. And in four different modes of fire, the microstructure and composition of molten metal marks was of significant difference, that is： （1） the average grain size of molten marks by a short circuit fire was about 3 -5μm, and its Cu20 was the lowest; melt marks by circuit overload had an average grain size similar to short-circuit, but their Cu2O content was about 30%; （2） melt marks by secondary short-circuit contained a certain number of larger diameter micro- hole, and their average grain size was about 30/,m; broadening and splitting provision of the diffraction peaks of Cu and Cu20 showed that their ablation was the deepest; （3） melting marks by fire showed the equiaxed maximum intensity of Cu2O diffrac- tion peaks, and there was almost no micro-boles.