广东“南澳Ⅰ号”明代沉船出水铜器腐蚀产物分析

由于海水环境中含有大量氯化物,海洋出水铜器在出水前已发生腐蚀,生成铜的氧化物及氯化物等。本文以广东"南澳Ⅰ号"明代沉船出水的22件铜器残片为研究对象,运用X-射线荧光仪(XRF)、X-射线衍射仪(XRD)和扫描电镜与能谱仪(SEM-EDS)等分析其腐蚀产物和矿物组成,结果表明腐蚀产物主要为铜的碱式氯化物,如Cu2(OH)3Cl和Cu(OH)Cl等,与国外已有研究成果类似,但Cu(OH)Cl在国外海洋出水铜器腐蚀产物中并不常见。     

Reburial and Analyses of Archaeological Remains in the Marine Environment — Investigations into the Effects on Metals

Abstract

The treatment and long-term storage of recovered cultural material from underwater heritage sites is becoming less cost effective, and reburial of archaeological sites and the associated artefacts in the marine environment is becoming increasingly common practice in managing the submerged cultural resource. Following recent large-scale underwater archaeological excavations in Marstrand harbour, Sweden, the majority of recovered finds were reburied in defined trenches in the harbour sediment. Subsequently, the Studio of the Western Sweden Conservators in conjunction with the Bohus County Museum initiated a fifty-year research project to evaluate reburial as an appropriate method of preserving waterlogged archaeological artefacts in the long term. The research project, entitled ‘Reburial and Analyses of Archaeological Remains’, was launched in 2002 and consists of six sub-projects. The main aims of these sub-projects are to analyse the extent of deterioration of the most common material types found on underwater archaeological sites, assess the stability of packing and marking materials used in archaeological documentation, and monitor the reburial environment.

The aim of the metals sub-project is to investigate the short- to long-term corrosion behaviour of metals buried in the marine environment by examining the deterioration of reburied and exposed modern metal coupons and eventually compare these results to the analysis of actual shipwreck artefacts. The environmental monitoring sub-project is designed to complement the other sub-projects by assessing the physico-chemical changes occurring in the reburial environment over time and the effect on the deterioration of the different reburied material types. In comparing the results obtained over the past seven years from both the metals and monitoring sub-projects, it should be possible to more accurately evaluate the effectiveness of reburial as a long-term in situ preservation strategy for metallic archaeological remains.     

Post-depositional surface whitening of ceramic artifacts: alteration mechanisms and consequences

Surfaces on ceramic artifacts that are paler than the main sherd body are commonly interpreted as slips that were intentionally applied by the potter during the manufacturing process. However, due to post-depositional alteration, sherds that were not originally coated with a slip may macroscopically appear with deceptively similar pale surfaces. This paper presents a comparison of two sherds, both with pale to white surfaces, one of which is a real slip and the other a surficial corrosion that occurred during the burial stage. Observations using optical and scanning electron microscopy, as well as electron-probe image- and microanalysis, clearly illustrate the features of the two surfaces, as well as demonstrating their causes and effects. The superimposed slip is clearly delimited from the sherd body by a denser and much finer-grained fabric, in which clay minerals predominate and porosity is reduced by about 20% compared to the body. In the other sample, surface corrosion, due to invading fluids, has led to leaching of calcareous constituents and results in a remarkable increase in porosity close to the rim (ca. 25%). Sometimes called the “espresso crema effect” (Tschegg et al., 2009b), the surface becomes considerably brighter than the core and can easily be confused with intentional slips. This, as a consequence can lead to significant misinterpretations, to erroneous sherd characterizations and classifications, as well as to incorrect assignments to specific ware groups.     

青铜病的闭塞孔穴腐蚀特征的研究

为探求符合文物保护要求的青铜器保护处理方法,对青铜病形成的过程和原因进行了模拟小孔腐蚀实验研究。对青铜模拟闭塞电池内的化学和电化学状态的变化,进行了不同Cl~-浓度和不同的pH值溶液条件下的电化学测试。实验结果证明,青铜闭塞孔穴腐蚀能导致蚀孔内Cl~-浓缩,pH值降低,腐蚀电流增大,局部腐蚀的加速,导致青铜病的形成。青铜病的闭塞孔穴腐蚀特征的研究,对进一步探求符合文物保护要求的青铜器保护处理方法具有较好的理论指导意义。     

杭州萧山老虎洞遗址出土青铜工具的金相分析及腐蚀探讨

杭州萧山老虎洞东周遗址出土两件青铜工具,工具出土时已碎裂为数段,锈蚀状态严重。针对两件青铜工具的研究,主要从微观领域来探讨青铜工具的工艺技术及腐蚀特点,并通过建立电化学反应模型,运用电极电位差的理论,来试析电极电位对金相组织腐蚀的影响。同时提出在青铜修复时,可利用电极电位的原理来补配修复材料,以达到文物保护的目的。     

Early Concrete Structures: Patented Systems and Construction Features

ABSTRACT

Reinforced concrete structures came to Spain in the late-19th century, somewhat after the development of this new construction material elsewhere in Europe. Their introduction was pioneered in industrialized areas, especially Northern Spain, under systems first patented in other European countries. Local constructors built structures under patents with little or no explanations to account for calculation, design, and construction technique. Some of these buildings from the recent past are now listed buildings. This study centres on three construction projects under patented systems: Our Lady of “La Antigua”, Orduña (Monier system), “La Ceres” flour mill, Bilbao (Hennebique system), and Alhóndiga, Bilbao (Blanc system). Preliminary structural studies analyzed morphology, reinforcements, concrete strength and pathological processes in each structure. Their results are compared with information taken from the patent systems in use at the time. This useful information on the structures, which may be expanded in future research, clearly describes the relationship between patent specifications and reality.     

Managing a Monitor — the Case of HMVS Cerberus in Port Phillip Bay: Integration of Corrosion Measurements with Site Management Strategies

Abstract

The hull of the former HMVS Cerberus (1926) collapsed two metres during gales in December 1993, leaving the vessel half-submerged. Sunk as a breakwater in 1926, the vessel is one of the few remaining and accessible twin-turret Monitor-style warships from the 1870s. This paper presents the complex history of attempts to stabilize the site and to preserve the wreck. A series of in situ corrosion studies of corrosion potentials, pH, and residual metal thickness have provided a special insight into the processes of decay and have paved the way for future site stabilization. Removal of the four 16-tonne 10 inch Armstrong rifled muzzle loading guns and their in situ treatment alongside the wreck have assisted in relieving some of the stress on the remaining structure. The paper reports on correlations between the corrosion rate and the formation of concretions and how to determine the end point of an in situ treatment for cannon.     

In-situ Corrosion Studies on Wrecked Aircraft of the Imperial Japanese Navy in Chuuk Lagoon, Federated States of Micronesia

A preliminary in-situ corrosion survey of the submerged Japanese WWII aircraft in Chuuk Lagoon, in the Federated States of Micronesia, has provided information on the way in which the wrecks interact with the marine environment. The aircraft are characterised by a lack of encrusting marine organisms and are clearly identifiable. The values of pH and the corrosion potentials vary with depth and the voltage depends on the composition of the underlying metal alloys. It is possible that with additional data from these non-destructive methods techniques it will be possible to provide marine archaeologists with appropriate diagnostic tools.
© 2006 The Author.     

铁器文物腐蚀与保护的研究现状

影响铁器文物腐蚀的主要因素有氧化气氛、潮湿环境、土壤的酸碱性环境和可溶性环境.本文介绍了铁器腐蚀的主要产物以及研究铁器文物腐蚀的主要方法,综述了目前国内外对铁器文物腐蚀和保护研究的最新进展.     

石质文物表面墨迹的保护作用

在许多不可移动石质文物,尤其是石刻文字表面,因历代文人墨客的拓片留下了大量墨迹。这些墨迹是否对文物本体岩石有害?一直是保护工作者希望了解的问题之一。为此本研究开展了一系列调研和实验研究。通过对各地保存较完好的石刻表面的观察,可以发现石刻表面残留的墨迹具有某种保护作用;对模拟样块的SO2腐蚀实验结果表明,岩石表面的墨迹具有一定的阻止空气中腐蚀性气体侵蚀岩石的作用;盐迁移破坏实验也发现墨迹在某种程度上具有减小可溶盐结晶破坏岩石的作用。吸水率实验和电镜观察等结果显示,墨迹缓解岩石风化的机理主要是墨迹对岩石微裂隙具有填充和加固作用,使岩石的吸水系数降低,部分阻挡了可溶盐的入侵和聚集结晶。