![]() ![]() ![]() It is the 5th most traded currency as of April 2022. 'People's Currency' symbol: ¥ ISO code: CNY abbreviation: RMB) is the official currency of the People's Republic of China. ![]() The renminbi ( Chinese: 人民币 pinyin: Rénmínbì lit. 129-136." Renminbi" in Simplified (top) and Traditional (bottom) Chinese characters Silva, M.F.Araújo, F.M.Braz Fernandes - "Multiphase microstructures on late imperial Chinese brass coins", Proceedings of theVIIConference on the Beginnings of the Use of Metals and Alloys (BUMA VII), September 13-17, 2009, Bangalore, India, (ISBN No. Braz Fernandes, "Some Corrosion Issues in Ancient Chinese Brass Coins: Influence of Minor Elements in Corrosion Susceptibility", Proceedings of Eurocorr 2010 (European Corrosion Congress)September 13-17, 2010,Moscow,Russia(Published in CD-ROM Conference Proceedings, ISBN 9781617824029), pp 2163-2171. Braz Fernandes, “Influence of Minor Elements in Ancient Chinese Brass Coins Microstructures”, TOFA-2010 (Discussion Meeting on Thermodynamics of Alloys), 12-15 September, 2010, Porto, Portugal, (submited for publication) (ISBN: 978-972-752-126-5). Braz Fernandes, “Composition and microstructures of imperial brass Chinese coins”, Mater. Lisbon (Portugal), August 2011 Oral presentation and published with the same title and author in Numismática, 114, (38/4). Moedas Imperiais Chinesas da colecção do Museu do Centro Científico e Cultural de Macau. Also, the corrosion susceptibilities in bronze and brass metallic phases, can contribute to an improved macroscopic diagnose for conservation purposes in similar items.Īll the results obtained during this study support the coins authenticity. The obtained results are an added value to the characterization of similar alloys, namely through the co-relation between their elemental contents and the current micro-constituents. Also, the presence of some minor elements was found to greatly influence the corrosion susceptibility, demoting (e.g., Fe) or promoting (e.g., Sn, Sb and As) the corrosion resistance of the phases in which these elements are in higher concentration. When considering brass coins, the most common corrosion process was dezincification. Metallographic techniques used in the study of 109 coins microstructures could confirm the production process consistency (sand casting), and establish a parallel between the elemental contents (obtained by micro-EDXRF) and the present metallic phases (observed by OM and SEM, and analyzed by SEMEDS and micro-XRD), resorting to equilibrium phase diagrams.Ī comparison between the corrosion susceptibility of metallic phases in bronze coins showed preferential transglobular corrosion of lead-rich globules and also that lead and/or tin corrosion byproducts are often deposited at the surface of these coins. Brass coins were found to be rich in zinc (<63 wt.%), but often presented traces or small contents of lead, tin, antimony, iron and arsenic. In bronze coins one of the main constituents was lead, which sometimes presented considerable content variations between the obverse and reverse of the same coin. In spite of the considerable number of similar items that populate museums and private collectors in Europe and North America, studies carried out in the western world are very scarce.įirstly, elemental characterization by EDXRF spectrometry was performed on 380 copper-based coins, revealing different types of alloys (coppers, bronzes and brasses) with variable alloy elemental composition. The Chinese cast coin collection from the CCCM’s Museum in Lisbon (Portugal) was accessible for analytical and metallographic studies. Project developed in the framework of a PhD in Conservation and Restoration by Maria João Furtado CHINESE COINS made of copper based alloys: elemental and microstructural characterization ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |