ADVANCED MATERIALS & PROCESSES | MAY/JUNE 2025 23 Forensic metallurgy, whether applied to archaeology or aerospace engineering, has very different purposes. However, the general procedures are similar. The required technical expertise is also broadly similar, even though the materials and specialist knowledge are very different. This need not be a problem, since detailed forensic investigations rely on teamwork. Although the procedures are similar, as described in Tables 1 and 2, the purposes and data collected for the actual investigations are different, as follows: • Archaeometallurgical analyses chiefly concern the descriptions and origins (provenances) of ancient metallic artifacts. The analyses are influenced by the artifacts’ rarity and value, and modern cultural heritage management (CHM), which includes practical and ethical aspects. In other words, invasive analysis may not be permitted, any sampling must be minimized, and any restorations should be reversible. This latter requirement can be controversial. • Engineering analyses are directed to solving operational problems with minimal time, effort, and costs. While fractography of failed components is (or should be) essential, FORENSIC METALLURGY IN ARCHAEOLOGY AND AEROSPACE The techniques used in forensic metallurgy investigations follow a similar protocol, whether the subject in question is a historical artifact or an aircraft component. This article looks at examples of invasive and noninvasive approaches as they apply to archaeometallurgy and aerospace applications. Russell Wanhill,* Caligula University Emmeloord, the Netherlands *Member of ASM International that the alloy was not intrinsically brittle during cracking[4]. The analysis concluded that the most probable fracture mode was stress corrosion cracking (SCC)[4]. This conclusion was based on invasive investigations of other ancient metallic artifacts, especially silver[5-7]. SCC would have been caused by residual stresses from riveting and burial (soil loads), combined with the burial environment, other scientific investigations could be considered secondary and judiciously omitted. Also, some or much background information may be unavailable or considered proprietary by the original equipment manufacturers (OEMs). Four examples of noninvasive and invasive archaeometallurgical and aerospace case histories are summarized in the following sections of this article. NONINVASIVE: THE ENKOMI CUP This high-status silver alloy cup dates to about 1400 BC and was found broken within a tomb in Cyprus in the 1940s. Figure 1 shows the visibly cracked cup in the cleaned and restored condition[1,2]. More background information is given in Refs. 1-4. A noninvasive investigation was begun In August 2021 to determine the nature of cracking and whether it could still threaten the cup’s restored integrity. This investigation had to be based on macrophotographic analysis only. The analysis covered the main crack origins, the cracking pattern, and associated distortions due to plastic deformation. This association meant Fig. 1 — The restored Enkomi cup showing the major cracks, their coalescence, and the locations of six rivets joining the cup to its handle. Note also the arrest locations of the coalesced cracks.
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