Metallographic Investigations of Silver Alloys Used for Minting

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A typical metallographic preparation (i.e. mechanical grinding and chemical etching) and electrochemical etch-polishing was carried out to observe the microstructure of pure silver and two silver-copper alloys (Sterling silver Ag 925 and Ag 333) in circular blanks used for coin production. The obtained micrographs revealed cold working effects on the coin rim caused by the rimming process. These rim effects are the reason for local differences in the mechanical properties of circular blanks, posing a challenge to tool lifetime. To quantify these effects, a micro hardness-mapping was performed and analysed.

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89-94

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March 2017

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© 2017 Trans Tech Publications Ltd. All Rights Reserved

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[1] P. Hammer, Metals and Mint. 1993, Stuttgart: Deutscher Verlag für Grundstoffindustrie, 9-16 (in German).

Google Scholar

[2] G. Beck, et al., Precious Metals - Manual of Practice. 1995: Hüthig - Verlag Heidelberg (in German).

Google Scholar

[3] American Society for Metals, International. Handbook Committee, Metals Handbook: Volume 2: Properties and Selection: Nonferrous Alloys and Special- Purpose Materials. 1990: ASM International.

DOI: 10.31399/asm.hb.v02.9781627081627

Google Scholar

[4] Buehler SumMet, The Science Behind Materials preparation. 2013; Available from: http: /www. buehler-met. de/fileadmin/user_upload/pdf/buyersguide/ Buehler_SumMet_DE_01. pdf.

Google Scholar

[5] G. Vander Voort. Metallographic Procedures for Precious Metals. 2012 [cited 2014 02. September]; Available from: http: /www. georgevandervoort. com/metallography-articles/1251-metallographic-procedures-for-precious-metals. html.

Google Scholar

[6] G. Petzow, Metallographic, Ceramographic, Plastographic Etching. Materialkundlich-technische Reihe 2006, Berlin: Borntraeger (in German).

Google Scholar

[7] T. Jones, Electropolishing of precious metals, Metal Finishing 102 (2004) 45-57.

DOI: 10.1016/s0026-0576(04)84698-1

Google Scholar