Search Results for chemical analysis

This study characterizes a historical Decauville narrow-gauge rail from Argentina (circa 1884) using metallographic analysis, chemical composition testing, and microhardness measurements. The rail, manufactured by French engineer Paul Decauville's company for portable agricultural and industrial transport, exhibited a hypoeutectoid steel composition (0.52% C) with ferrite-pearlite microstructure showing cold deformation patterns from service stress. Chemical analysis revealed a composition comparable to modern European rail steels, while microhardness values met current rail standards. Macrographic examination confirmed excellent material quality with no manufacturing defects. The study demonstrates that this 19th-century rail achieved contemporary quality standards through controlled manufacturing processes, with service-induced cold deformation enhancing mechanical strength and wear resistance.

Forensic metallurgy investigations in archaeology and aerospace engineering follow similar technical protocols but serve different objectives. Archaeometallurgical analyses focus on artifact provenance and cultural heritage management with minimal invasive sampling, while aerospace investigations prioritize rapid failure analysis for operational problems. Four case studies illustrate the approaches: noninvasive macrophotographic analysis of an ancient silver cup revealed stress corrosion cracking, noninvasive investigation of a Boeing 747 accident identified fatigue failure in fuse pins due to inadequate load knowledge, invasive lead isotope analysis successfully provenanced Chinese bronzes using kernel density methods, and comprehensive testing of F-16 wing bolts ruled out hydrogen embrittlement. Both fields employ similar analytical techniques, including microscopy, fractography, and chemical analysis, but differ in sampling constraints, time pressures, and reporting goals, with successful investigations in both domains requiring interdisciplinary teamwork.

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.

New electrical, mechanical, and chemical testing capabilities give scanning electron microscopes the feel of a self-contained “nano-laboratory.” Several developments in SEM technology allow new and more flexible approaches to the analysis of novel systems, such as Li battery-related materials, nanostructured and nanoporous materials, and novel approaches to 3D analysis.

This case study details the noninvasive analysis of an 5000-year-old silver figurine from Iran, now in the collection of The Metropolitan Museum of Art. The The object of this study, a figure of a kneeling bull clothed in a robe with a stepped linear pattern and holding up a spouted vessel, is composed of 15 pieces of worked silver joined together with silver solder. The aim of the study is to apply noninvasive micro-xray fluorescence spectroscopy (μ-XRF) analysis to characterize the silver alloy compositions and compare the new data with previously obtained results from invasive chemical analyses of samples performed by thermal neutron activation.

Enhanced mining tool performance is achieved through the use of reclaimed NiCrBSi-WC powders in laser metal deposition. Collection, analysis, and reuse of spilled powder lowers production costs and reduces environmental impact.

This article reviews the analytical techniques used for phase identification in components, including x-ray diffraction, metallography/microscopy, electron backscatter diffraction, trasmission electron microscopy,and atom probe tomography. The article addresses the advantages and disadvantages of each technique compared to the other approaches.

As high-entropy alloys become more complex in terms of microstructure, phase stability, and intermetallics, the advent of sophisticated analytical instruments is helping scientists to develop new materials with the most desirable properties. The analysis techniques described in this article include electron energy loss spectroscopy, electron probe microanalysis, atom probe tomography, and x-ray absorption spectroscopy.

By changing a setup and using electron transparent samples, hundreds of laboratories worldwide have access to a characterization technique, transmission Kikuchi diffraction, that measures grain sizes and orientations in nanocrystalline materials.

A metallurgical study of a 10th century iron-base nail from the central-East coast of Tunisia reveals how early metallurgists without modern scientific knowledge created parts with engineered properties.

Difficulty in clearly and quantitatively answering questions concerning a component or product failure can lead to courtroom debates, arguments, and battles. The case studies in this article identify and describe technical procedures to assist with explaining complex situations and thereby assist in solving failure analysis problems and resolving legal disputes.

As powder-based additive manufacturing (AM) processes continue to mature, reliable powder characterization techniques will be key to optimizing both AM processes and final part performance. This article describes advanced metals for assessing powder properties and their influence on AM processing and part performance.

A study of metal artifacts from the Mendoza region of Argentina reveals the influences of native migration and European conquest.

Optimizing the integrity and performance of highly engineered surfaces and structures requires the ability to visualize and understand material behavior over multiple length and time scales from a three-dimensional perspective. The Electron Microscopy Centre at the University of Manchester is equipped for such work as demonstrated in problem-solving scenarios involving multiscale imaging and analysis of the progression of intergranular corrosion in Al alloy 2024, the catalytic effect of silver nanoparticles in seawater, recrystallization in a volume element of a bronze alloy, and defect progression on graphene surfaces.

An examination of a bearing failure due to mismatched and incomplete flame hardening shows the need to work with heat treaters for proper selection and application. The article includes a case study of a large bearing raceway that failed due to incomplete austenitization.

Understanding the forces behind decarburization is the first step toward minimizing its detrimental effects. This article reviews decarburization basics and results of experimental work on spring steels.

In order to expand the choice of materials available for use in additive manufacturing, parameters that consider welding metallurgy, laser powder interaction, and post processing must be developed. This article describes the outcomes of process development for a steel and stainless steel alloy that are not standard materials for laser powder bed fusion equipment.

Researchers at the Center for Heat Treating Excellence (CHTE) at Worcester Polytechnic Institute (WPI) are working with CHTE members to develop post-processing parameters to enhance the mechanical properties of additively manufactured (AM) steels. This article reports preliminary results based on characterization of AISI 8620 and 20MnCr5 powder, selective laser melted parts, and wrought parts.

A recent metallographic and historical analysis of two parts from the Buenos Aires to Pacific Railroad railway looked at possible manufacturing techniques of the parts in question. The information collected is useful for comparison with techniques and materials used at that time as well as with current techniques. The analysis questioned whether the material itself has varied or evolved from the metallurgical point of view, and confirmed the quality of raw material used to construct the historic railway line.

Steel pioneer Henry Marion Howe was an industrialist, scientist, teacher, writer, and lifelong researcher. Howe’s reputation developed due to three books he wrote on steel. His major legacy, however, is based on his metallography courses. Many of his students became important contributors to the development of metallography as an art and science.