Microstructural characterisation of five simulated archaeological copper alloys using light microscopy, scanning electron microscopy, energy dispersive X-ray microanalysis and secondary ion mass spectrometry

Abstract

This paper describes the microstructural characterisation of five simulated archaeological copper alloys, produced by modern powder technology. The chemical composition of the examined bronzes covers the major families of archaeological bronzes from antiquity until the Roman period. Light microscopy (LM), energy dispersive X-ray microanalysis (EDX), scanning electron microscopy (SEM) as well as two-and three-dimensional secondary ion mass spectrometry (SIMS) have been used to describe the main properties of the alloys. The results show a heterogeneous microstructure on a micrometer scale, formed by metallic and non-metallic phases. The latter are conglomerates of oxides or sulphides of major or minor elements.

Large scale smelting of speiss and arsenical copper at Early Bronze Age Arisman, Iran

“…In contrast, our analyses of BCR 691 Alloy C, arsenical copper with certified 4.6 wt% As, differed more than 40 percent relative to the certified value, typically reporting between 6.1 and 7.1 percent As. However, these alloys were developed for use with XRF analysis and not for microbeam analysis, and Constantinides et al (2001) reported major chemical heterogeneities for this set of alloys, including the presence of numerous sulphide and oxide inclusions in the arsenical copper alloy. Future work will focus on the reliable quantitative analysis of arsenical copper prills using microbeam analysis; for the time being we use the arsenic values of our analyses as reported by the SEMeEDS software.…”

The role of SIMS in cultural heritage studies

“…In the area of art and archaeometry, SIMS has been applied successfully to a wide range of materials, including pigments [2,3], glasses [4][5][6][7][8][9][10][11][12][13], metal alloys and tarnishes [14][15][16][17], and human remains such as teeth [18]. Here we describe in more detail the use of both dynamic and static SIMS for some selected applications.…”

“…SIMS has been used to examine these samples previously [30]. In this experiment, a sample was polished and exposed to air to oxidise overnight.…”

Old master paintings – A fruitful field of activity for analysts: Targets, methods, outlook

“…The discussed inorganic species were identified in wall [9, 40, 83, 89 -92, 94], paper [9,82,85,87,93,95], canvas [32,84,88,96,97], and sculpture [84,98,99] paintings, as well as in ceramic glazes [100 -102], jewelry products [103], laboratory prepared painting layers [17], and simulated archaeological copper alloys [104]. As was mentioned above, the identification is performed mainly by use of spectral methods, which allow non-destructive analysis of very small spots from the object.…”