This article summarizes the more common analytical techniques for studying ancient metal artifacts, illustrated by case histories. There are two main classifications: noninvasive and invasive techniques. This distinction is of prime importance because some heritage objects may be too rare or valuable for invasive sampling, or there may be ethical objections to certain types of examination. Noninvasive examination of ancient metal artifacts is important, yet it cannot provide the detailed information obtainable from invasive techniques. This is especially true when artifacts contain “hidden” damage and there is also a need for accurate quantitative analyses.

Although stress corrosion cracking (SCC) accounts for just a fraction of all engineering failures, its prevention is a major problem, particularly in the aerospace industry. Recent archaeometallurgical studies show that stress corrosion cracking occurred in ancient metallic artifacts. This article describes investigations that revealed definite evidence for SCC in ancient silver and bronze alloys and a probable case of SCC in low-carat (13K) gold. Diagnostic methods included visual inspection, metallography, and fractography.

This article provides an overview of cracking and fracture mechanisms in heritage gold, silver, low-tin bronze, and wrought iron alloys. Understanding these mechanisms can be important for restorers, and possibly for conservators and curators as well. Metallography is widely used (when sampling is permitted) for studying archaeometallurgical artifacts in detail. However, fracture surface examinations and analysis (i.e., fractography) can often provide even greater insight. Case studies demonstrate the benefits of employing fractographic analysis to study cracking and fracture mechanisms in heritage alloys.

Nitinol fatigue fracture surfaces generally exhibit similar features to most engineering alloys, including a flat fracture plane, ratchet marks, radial lines, beachmarks, and striations.

Development of new, radiation-tolerant materials that maintain the structural integrity and safety margins over the course of a nuclear power reactor’s service life requires the ability to predict degradation phenomena. Modern post-irradiation examination methods make use of specialized high-flux test reactors and dedicated characterization facilities to limit occupational exposure and prevent the spread of radioactive contamination. This article illustrates the use of these advanced techniques to characterize precipitates in neutron-irradiated Fe-Cr-Al alloys.

Fasteners play a critical role in engineered structures as a method of nonpermanent joining for the aerospace, infrastructure, civil, automotive, energy generation/distribution, and many other industries. Fastener failures can lead to disastrous consequences and substantial financial losses. One of the most common fastener failure modes is fatigue crack initiation and growth. Inadequate design considerations, material problems, insufficient preload, loosening, and excessive loads can all contribute to fastener fatigue. A case study of steel screw failures highlights some of the critical manufacturing and design factors that affect fastener fatigue.