巴蜀带斑纹兵器的锈蚀产物分析及机理探讨

带斑纹兵器是巴蜀兵器的一大特色。由于表面有斑纹的青铜兵器锈蚀与一般青铜器锈蚀有所不同,必须针对其特殊性进行锈蚀机理的研究,才能对症下药,达到有效保护的目的。应用矿相分析、SEM EDS、XRD等分析手段对几件巴蜀带斑纹兵器表面与截面锈蚀产物进行分析,并与非斑纹锈蚀进行比较;对斑纹与非斑纹的锈蚀机理进行探讨。分析结果表明,斑纹的锈蚀产物主要是SnO2,其在兵器斑纹表面形成钝性保护膜,防止其进一步腐蚀,对斑纹下面的基体有一定的保护作用。非斑纹层锈蚀向斑纹层下面的基体扩展,膨胀是造成斑纹层凸起甚至脱落的主要原因,对斑纹兵器保护的关键是控制非斑纹层锈蚀的进一步发展。

A study of corrosion mechanics of Bashu bronze weapons with mottle

Many Ba shu bronze weapons are mottled. The corrosion of these weapons is different from those without mottle. In order to solve their problem of rust and attain effective preservation, it is necessary to study the corrosion mechanics. SEM- EDS, XRD and microscopy were used in the analysis. This paper is a preliminary discussion of the corrosion mechanics. By using SEM- EDS to analyze three samples,it is shown that the tin content is about 12%. The lead content is lower. The micro- structure of the mottle layer is different from that of the bronze body. The tin content of the mottle layer is also much higher than that of its bronze body. The thickness of the mottle layer is about 20 - 40tun. The boundary between the matrix and the mottle layer can be seen clearly. SnO2 and Cu41Sn11 are the main substances of the mottle layer. The corrosion products of the non - mottle layer are oxidant of copper and some stable salts. The powdered corrosion of chloride is not severe. The different colors of the mottle layer and the matrix were caused by diverse corrosion products when they contacted the burial environment. SnO2 is the main product of the mottle layer. It forms a refractory surface to prevent further corrosion and protect subjacent matrix alloy. Non- mottle layer corrosion is extended to the matrix under the mottle and causes the mottle to drop off. The key to protect the weapons is to control non - mottle cormsion.