Study of the corrosion of copper coins from the wreck of “The South China Sea No.1â€
Dublin Core
Title
Study of the corrosion of copper coins from the wreck of “The South China Sea No.1â€
Description
The South China Sea No.1 is the wreck of the longest, largest and most preserved shipwreck site in China. It is a classic example of bireme construction and navigational technology. The artefacts located on the site may provide many secrets of the Silk Road on the sea. Therefore, the archaeological value is greater than its economic value. In order to know more about the craftwork and the state of the coppers in this wreck, this paper will examine the concretion and corrosion on the surface of copper samples obtained from the upper layer of South China Sea No. 1. The samples were analysed with metallographic microscopy, 3D video microscopy, X-ray diffraction (XRD),X-ray fluorescence （ XRF) and scanning microscopy (SEM-EDS). The results show that the copper coin is tin-lead bronze, and the content of Cu is about 94%. The corrosion is mainly Cu2(OH)3Cl, Cu2O, Cu(OH)2, Cu(OH)Cl and Cu(SO4)2. The concretion on the surface of the copper coin is rich, but the matrix becomes thinner. Lead (Pb) is scattered freely in the matrix. Tin (Sn) is high in the corrosion layer, which shows that some Cu has corroded. The electrochemistry of the corrosion was controlled by oxygen depolarization. Selective corrosion occurred between Cu and Sn, and the effect of Cl- sped up the rate of corrosion in the electrochemical reaction. The results of the study can provide a reference for the protection of the copper artefacts excavated from South China Sea.
Creator
Xing-ling Tian
Nai-sheng Li
Zhi-guo Zhang, in Van Tilburg, H., Tripati, S., Walker Vadillo, V., Fahy, B., and Kimura, J. (eds.)
Date
5/15/2014
Files
Collection
Citation
Fatal error: Uncaught ValueError: version_compare(): Argument #3 ($operator) must be a valid comparison operator in /home/kknoerl/themua.org/collections/application/libraries/Zend/Xml/Security.php:172 Stack trace: #0 /home/kknoerl/themua.org/collections/application/libraries/Zend/Xml/Security.php(172): version_compare('8.0.30', '5.6', 'gte') #1 /home/kknoerl/themua.org/collections/application/libraries/Zend/Xml/Security.php(76): Zend_Xml_Security::isPhpFpm() #2 /home/kknoerl/themua.org/collections/application/libraries/Zend/Xml/Security.php(150): Zend_Xml_Security::scan('<?xml version="...', NULL) #3 /home/kknoerl/themua.org/collections/application/libraries/Zend/Locale/Data.php(160): Zend_Xml_Security::scanFile('/home/kknoerl/t...') #4 /home/kknoerl/themua.org/collections/application/libraries/Zend/Locale/Data.php(232): Zend_Locale_Data::_findRoute('en_US', '/ldml/dates/cal...', '', 'pattern', Array) #5 /home/kknoerl/themua.org/collections/application/libraries/Zend/Locale/Data.php(1137): Zend_Locale_Data::_getFile('en_US', '/ldml/dates/cal...', '', 'pattern') #6 /home/kknoerl/themua.org/collections/application/libraries/Zend/Date.php(843): Zend_Locale_Data::getContent('en_US', 'date', Array) #7 /home/kknoerl/themua.org/collections/application/libraries/Zend/Date.php(580): Zend_Date->_parseIsoToDate('FFFF', 'en_US') #8 /home/kknoerl/themua.org/collections/application/libraries/Zend/Date.php(466): Zend_Date->_toToken('FFFF', 'en_US') #9 /home/kknoerl/themua.org/collections/application/libraries/globals.php(1006): Zend_Date->toString('FFFF') #10 /home/kknoerl/themua.org/collections/application/models/Item.php(489): format_date(1721302222, 'FFFF') #11 /home/kknoerl/themua.org/collections/application/models/Item.php(202): Item->getCitation() #12 /home/kknoerl/themua.org/collections/application/views/helpers/Metadata.php(169): Item->getProperty('citation') #13 /home/kknoerl/themua.org/collections/application/views/helpers/Metadata.php(144): Omeka_View_Helper_Metadata->_getRecordMetadata(Object(Item), 'citation') #14 /home/kknoerl/themua.org/collections/application/views/helpers/Metadata.php(73): Omeka_View_Helper_Metadata->_getText(Object(Item), 'citation') #15 /home/kknoerl/themua.org/collections/application/libraries/Zend/View/Abstract.php(349): Omeka_View_Helper_Metadata->metadata(Object(Item), 'citation', Array) #16 /home/kknoerl/themua.org/collections/application/libraries/globals.php(2042): Zend_View_Abstract->__call('metadata', Array) #17 /home/kknoerl/themua.org/collections/themes/berlin/items/show.php(33): metadata('item', 'citation', Array) #18 /home/kknoerl/themua.org/collections/application/libraries/Omeka/View.php(114): include('/home/kknoerl/t...') #19 /home/kknoerl/themua.org/collections/application/libraries/Zend/View/Abstract.php(888): Omeka_View->_run('/home/kknoerl/t...') #20 /home/kknoerl/themua.org/collections/application/libraries/Zend/Controller/Action/Helper/ViewRenderer.php(912): Zend_View_Abstract->render(NULL) #21 /home/kknoerl/themua.org/collections/application/libraries/Zend/Controller/Action/Helper/ViewRenderer.php(933): Zend_Controller_Action_Helper_ViewRenderer->renderScript('items/show.php', NULL) #22 /home/kknoerl/themua.org/collections/application/libraries/Zend/Controller/Action/Helper/ViewRenderer.php(972): Zend_Controller_Action_Helper_ViewRenderer->render() #23 /home/kknoerl/themua.org/collections/application/libraries/Zend/Controller/Action/HelperBroker.php(277): Zend_Controller_Action_Helper_ViewRenderer->postDispatch() #24 /home/kknoerl/themua.org/collections/application/libraries/Zend/Controller/Action.php(527): Zend_Controller_Action_HelperBroker->notifyPostDispatch() #25 /home/kknoerl/themua.org/collections/application/libraries/Zend/Controller/Dispatcher/Standard.php(308): Zend_Controller_Action->dispatch('showAction') #26 /home/kknoerl/themua.org/collections/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http)) #27 /home/kknoerl/themua.org/collections/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(105): Zend_Controller_Front->dispatch() #28 /home/kknoerl/themua.org/collections/application/libraries/Zend/Application.php(384): Zend_Application_Bootstrap_Bootstrap->run() #29 /home/kknoerl/themua.org/collections/application/libraries/Omeka/Application.php(73): Zend_Application->run() #30 /home/kknoerl/themua.org/collections/index.php(23): Omeka_Application->run() #31 {main} thrown in /home/kknoerl/themua.org/collections/application/libraries/Zend/Xml/Security.php on line 172