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Coins were used to maintain the commercial activities on a specific standard. They are significant written sources that enlighten the political, economic, and cultural life of the period they were produced. It is possible to find the coin collections belonging to different periods of Turkish history in museums. One of the important groups of these coins belongs to the Ottoman period. Although there are studies covering the periods of some Ottoman sultans by using advanced analysis techniques in the literature, no scientific study has been carried out covering all periods. The most extensive information that can be found about the coins is from the Ottoman archive and inventory records. In this study, twenty-six Ottoman Empire coins from Sakarya Museum dated between the 14th-19th centuries were evaluated stylistically, physically, and chemically. The non-destructive analysis of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) was employed to identify the elemental composition of the coins. The chemical analysis of coins showed the connection between the political situation in the Ottoman Empire and the decline in the value of the money. [ABSTRACT FROM AUTHOR]

Additive manufacturing is proposed as a novel alternative to coin blank's production routes based on rolling, blanking and edge rimming. The presentation draws from laser powder bed fusion of cylinders, slicing into individual coin blanks by electro discharge machining and surface preparation by polishing, to coin minting in a laboratory press-tool system. Special emphasis is given to material deposition and coin minting due to the originality of producing coin blanks with complex intricate contoured holes and to the necessity of subjecting the additive manufactured coin blanks to extreme compressive stresses that are typical of coin minting. Numerical and experimental results confirm the excellent performance of the additive manufactured coin blanks. The new design layouts included in the additive manufactured coin blanks open the way to produce high value-added singular collector coins, which are disruptively different from those available in the market nowadays. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present a new hybrid additive manufacturing route for fabricating collector coins with complex, intricate contoured holes. The new manufacturing route combines metal deposition by additive manufacturing with metal cutting and forming, and its application is illustrated with an example consisting of a prototype coin made from stainless steel AISI 316L. Experimentation and finite element analysis of the coin minting operation with the in-house computer program i-form show that the blanks produced by additive manufacturing and metal cutting can withstand the high compressive pressures that are attained during the embossing and impressing of lettering and other reliefs on the coin surfaces. The presentation allows concluding that hybrid additive manufacturing opens the way to the production of innovative collector coins with geometric features that are radically different from those that are currently available in the market. [ABSTRACT FROM AUTHOR]

This paper describes a numerical and experimental route for application and validation of finite elements in coin minting based on an industrial case study. The numerical work encompasses virtual prototyping of the dies from three-dimensional models prepared by the sculptor and finite element simulation of the coin minting process. The experimental work comprised independent determination of the stress–strain curve of the disk material by means of stack-compression tests, verification of the force values provided by the industrial coin minting press and validation of the numerical estimates of the progressive filling of the relief coin features and of the force vs. die stroke evolution. Results show that finite elements can be successfully applied to predict material flow and filling of the intricate relief coin features as well as to estimate the required coin minting forces before fabricating the actual dies. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present a new hybrid additive manufacturing route for fabricating collector coins with complex, intricate contoured holes. The new manufacturing route combines metal deposition by additive manufacturing with metal cutting and forming, and its application is illustrated with an example consisting of a prototype coin made from stainless steel AISI 316L. Experimentation and finite element analysis of the coin minting operation with the in-house computer program i-form show that the blanks produced by additive manufacturing and metal cutting can withstand the high compressive pressures that are attained during the embossing and impressing of lettering and other reliefs on the coin surfaces. The presentation allows concluding that hybrid additive manufacturing opens the way to the production of innovative collector coins with geometric features that are radically different from those that are currently available in the market.