汉代陶罐表面结晶盐的成因及其腐蚀机理

Corrosion Mechanism and Formation Causes of Crystal Salt on a Han Dynasity Pottery Jar

为揭示陶罐表面结晶盐成因与腐蚀机理,利用超景深显微镜(DM)、离子色谱仪(IC)、扫描电子显微镜-能谱仪(SEM-EDS)、X射线衍射仪(XRD)等分析了陶罐表面盐分的化学组成和微观形貌。结果显示,表面结晶盐主要是氯化钠,结晶盐已引起陶罐表面胎体粉化脱落。盐分的主要来源,既有埋藏环境的土和地下水,也有降尘。同时保存环境温湿度的变化较大,诱发了陶罐表面盐分反复发生溶解结晶产生盐害。通过Na Cl的饱和溶解度和结晶学分析,发现相对陶罐所处环境中温度的变化,相对湿度的变化对Na Cl浓度变化影响较大,产生的结晶负压大。胎体粉化脱落主导因素为Na Cl结晶产生的结晶应力。在此基础上提出保护性建议。

To reveal the mechanisms of the surface crystal salt and erosion of pottery jar,the super depth of field microscopy(DM),X-ray diffraction(XRD),ion chromatography(IC),scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS)had been used to analyze the salt precipitation.The results show that the main composition of the crystak salt were sodium chloride(NaCl),which caused the pottery efflorescence and decay.The sodium chloride mainly came from soil and groundwater,the storeroom dust was also a source of the salt.The temperature and humidity of the storage environment varied greatly,which were triggers of the occurrence of the salt on the pottery jar.The effect of salt on the pottery were studied by the analysis of salt crystallography and saturation solubility.The results show that the change in relative humidity had a greater impact on the concentration changes of NaCl compared to the temperature change in the storage environment of the pottery jar.The main factor causing the pottery efflorescence and decay is crystallization stresses brought about by NaCl,based on which protective suggestions were put forward.