Magnetization of Ancient Ceramics

The saturation magnetization σ of soft baked pottery appears to be determined during the firing process by transitions between the iron oxides magnetite, maghemite, hematite and perhaps goethite. The finding of large variations in σ motivated the design and construction of a ‘magnetization–gravitation’, or ‘MG’, balance for rapid non‐destructive magnetization measurements. The first results with this MG balance are presented: iso‐σ contours, typical histograms and correlations with colour features. Practical MG applications are summarized.     

Mechanical Performance of Historical Wrought Iron Rods

Historical masonry buildings are often reinforced with ferrous tie rods. Before the late 18th century, such rods were hot formed by using wrought iron deriving from either the bloomery or the finery process; thereafter, the puddling process was introduced and gradually became prevalent. Several such tie rods are still in service in cultural‐heritage buildings; their analysis can shed light on historical production processes and building techniques, and knowledge of their mechanical performance can be valuable for architectural conservation purposes. Four steel tie rods, which were retrieved from a 17th century masonry building in Turin, Italy, and are dated to the late 17th and early 19th centuries, are examined here, by means of chemical and microstructural analyses, tensile tests and fractographic examinations, and both the material fabrication procedure and its mechanical performance are discussed.     

Civil War Iron and the H.L. Hunley Iron Ballast

At the beginning of the American Civil War in 1861, the Union greatly outpaced the Confederacy in industrial manufacturing capabilities. The Confederacy's economy prior to the conflict was largely based on agriculture, and the Southern states lacked the facilities and skilled labourers to produce iron on the scale necessary to compete with the Union. The possibility of importing products was greatly diminished when President Lincoln instituted a naval blockade around major Southern ports, limiting the amount of cargo that could be imported from Europe. Consequently, the Confederacy was forced to adapt ironworks to wartime purposes. Despite these adaptations, the Confederacy suffered from iron shortages throughout the war. This paper uses the iron ballast found on the Confederate submarine H.L. Hunley as a case study for the manufacturing processes, labour relationships and social significance of iron production and usage in the Confederacy.     

钧瓷天蓝、天青釉色中氧化铁的呈色作用

氧化铁在钧瓷天蓝、天青系列釉色中的着色作用以及乳光蓝色问题,一直是学术界争论的焦点。本研究通过放大氧化铁含量的实验验证方法,通过SEM(scanning electron microscope-扫描电子显微镜)、EDS(Energy Dispersive Spectrometer-能谱仪)、XRD(X-ray diffraction-X射线衍射)等分析方法,重点研究了基础组成和分相结构对釉中氧化铁呈色的影响。同时,作者通过验证研究得出,钧瓷天蓝、天青系列釉色中,真正起呈色作用的是釉中的氧化铁等着色剂,第二相微粒散射呈色并非钧釉的普遍现象,或只是辅助呈色作用。     

Studying the Cannons of Punta Santa Anna,Spain: In Situ Conservation,Promoting Public Access,and Monitoring Iron Corrosion

The 2001 UNESCO convention for the Protection of Underwater Cultural Heritage (UCH) encourages and supports projects that would make accessible to the general public underwater cultural sites. Since 2010 the Catalonian Federation of the World Underwater Federation (FECDAS), have been developing outreach activities with the objective of promoting the protection of the UCH among recreational scuba divers. The purpose of this paper is to introduce one such project, the Punta Santa Anna in Blanes, Spain. This project has three objectives: the promotion of UCH to the general public, the in situ protection of this underwater archaeological site, and a case study on iron corrosion processes. FECDAS/CMAS will create an underwater archaeological park where recreational scuba divers will be able to visit some purposely selected archaeological iron cannons. To expose UCH to the general public will potentially affect the integrity of these artefacts. This risks potential damage and so, with the objective of minimizing potential threats, a series of protective measures and a systematic monitoring programme have been planned. The programme is designed to study the relationship between the underwater environment and the artefacts. The aim is to acquire a better understanding of the corrosion processes of iron objects present in marine underwater sites.     

新乡火电厂汉墓群出土九件铁制容器

2003年底至2004年初,在新乡火电厂抢救性发掘汉代墓葬200余座,出土9件鼎、壶、釜等铁制容器.墓葬时代应为西汉早、中期.特别是出土的两件大型铁壶属河南省内首次发现.     

上海青龙镇唐代铸造作坊遗址出土陶范的分析研究

上海青龙镇相传始建于公元746年,是上海地区最早的对外贸易重镇。2012年青龙镇的考古发掘中发现了 4座熔炉以及熔炉周围堆积的大量陶范、炉渣等,是上海地区首次发现的冶铸作坊遗址,遗址使用的主要年代是唐代晚期。为了解青龙镇唐代铸造作坊遗址出土陶范的制作技术,对遗址出土的陶范进行分析研究,以期揭示唐代青龙镇铸造作坊的制范技术。对陶范型腔面上残留的附着物分析主要元素是铁,表明陶范用于铸造铁器。经分析遗址中出土的陶范由三层组成:面层、背层和稻壳泥层。面层厚约1～2 mm,采用细颗粒泥料制作,致密,在铸造铁器时能确保陶范承受高温液态金属的充型压力,并得到表面光洁的铸件。背层厚约4～7 mm,该层羼入了粗颗粒物,这些羼和料可以减少陶范在干燥收缩和焙烧过程中的收缩变形。稻壳泥层厚约11～16 mm,该层羼入了一定量粗颗粒物,并羼入了大量的稻谷壳,陶范焙烧时谷壳烧失,在陶范上留下了大量的孔隙,便于铸造时型腔中气体的排出。三种不同的材质起到不同的作用,以保证成功铸造出铁器。在冶铸作坊废弃后在其上建造的一口水井内发现的铁釜、铁提梁鼎的形状与遗址中出土陶范所铸器物的形状吻合,应为该遗址所铸造器物。     

Bleached mudstone,iron concretions,and calcite veins: a natural analogue for the effects of reducing CO2‐bearing fluids on migration and mineralization of iron,sealing properties,and composition of mudstone cap rocks

This study investigates the Wangfu Depression of the Songliao Basin, China, as a natural analogue site for Fe migration (bleaching) and mineralization (formation of iron concretions) caused by reducing CO₂‐bearing fluids that leak along fractures after carbon capture, utilization, and storage. We also examined the origin of fracture‐filling calcite veins, the properties of self‐sealing fluids, the influence of fluids on the compositions of mudstone and established a bleaching model for the study area. Our results show that iron concretions are the oxidative products of precursor minerals (pyrite and siderite) during uplift and are linked to H₂S and CO₂ present in early stage fluids. The precipitation of calcite veins is the result of CO₂ degassing and is related to CO₂, CH₄, and minor heavy hydrocarbons in the main bleaching fluids. In our model, fluids preferentially enter high‐permeability fracture systems and result in the bleaching of surrounding rocks and precipitation of calcite veins. The infilling of calcite veins significantly decreases the permeability of fractures and forces the fluids to slowly enter and bleach the mudstone rocks. The Fe²⁺ released during bleaching migrates to elsewhere with the solutions or is reprecipitated in the calcite veins and iron concretions. The formation of calcite veins reduces the fracture space and effectively prevents fluid flow. The fluids have an insignificant effect on minerals within the mudstone. In terms of the chemistry of the mudstone, only the contents of Fe₂O₃, U, and Mo change significantly, with the content of U increasing in the mudstone and the contents of Fe₂O₃ and Mo decreasing during bleaching.     

Metallurgical Characterization of A Coated Roman Iron Coin By Analytical Investigations

A coated Roman iron coin from Villa Loig in Salzburg, Austria was investigated. The coating is a copper alloy consisting of Cu, Pb, Sn, Zn and negligible amounts of Ag, a variant of gunmetal known as ‘leaded red brass’. The numismatic term for such a coin is subferratus (Latin). From an archaeometallurgical point of view, information about the chemical composition, the microstructure and the manufacturing technique are of interest. To achieve these objectives, different analytical techniques and metallographic examinations were applied. Droplet‐shaped iron inclusions were observed in the red brass coating, while at the grain boundaries, inside the iron core, copper and lead were detected (liquid metal embrittlement). The dendritic microstructure of the coating, the spheroidal‐shaped iron inclusions in the coating and the liquid metal embrittlement show that the iron coin was plated by immersing it in a molten copper alloy. The iron core is a low‐carbon steel with slag stringers, both of which are characteristic of a bloomery iron. Deformation twins (Neumann lines) were observed in the microstructure of the iron core and indicate that the coining was performed after the flan was cooled.