目的 通过对300、400、500 ℃热空气和燃烧气氛中5052铝合金表面氧化层退化行为的分析，研究基于火灾后金属材料表面产物分析来确定火场中是否存在助燃剂的方法。方法 使用高温氧化实验装置对火场中的燃烧气氛进行模拟，用光学显微镜、扫描电子显微镜（SEM）、X射线衍射仪（XRD）和精密分析天平对5052铝合金在300、400、500 ℃空气和燃烧气氛中表面氧化物的退化行为进行研究，并对氧化物层的组织结构进行分析。结果 5052铝合金表面氧化物层与外界环境气氛和温度密切相关，在温度较低的热空气中表现出较好的抗氧化性能，表面生成的氧化物层完整致密；高温燃烧气氛使5052铝合金的氧化速度显著提高，表面生成的氧化物层结构疏松，并随时间的延长出现失稳氧化。结论 火灾中铝合金表面氧化层的微观结构记录了火场的相关信息，这些信息不但是对传统残留物宏观形貌证据的有效补充，还可作为火场中是否有助燃剂存在的辅助证据使用。

The work aims to analyze the degradation of oxide scale on 5052 aluminum alloy in the hot air and combustion atmosphere of 300 ℃, 400 ℃ and 500 ℃, so as to study the method of determining whether there is accelerant in the fire scene based on the analysis of metal oxide scale after the fire. The combustion atmosphere in the fire scene was simulated by a high temperature oxidation experimental device. Optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and precision electronic balance were used to investigate the degradation of oxide scale on the surface of 5052 aluminum alloy in the air and combustion atmosphere of 300 ℃, 400 ℃ and 500 ℃ and analyze the microstructure. The oxide scale on the surface of 5052 aluminum alloy was closely related to the ambient atmosphere and temperature. Good oxidation resistance appeared in hot air with lower temperature, and the oxide scale generated on the surface was complete and compact. The oxidation rate of 5052 aluminum alloy was significantly increased by high temperature combustion atmosphere. The structure of oxide scale formed on the surface was loose and unstable oxidation occurred with time. The microstructure of oxide scale on aluminum alloy surface in fire records relevant information of fire scene, which is not only an effective supplement to macroscopic morphology evidence of traditional residue, but also can be used as auxiliary evidence for the presence of combustion improver in fire scene.