Metallurgical History Research Articles

Correlative analysis of advanced microscopy techniques for metallography and corrosion microstructures of bronze phoenician coins

Correlative microscopy stands out for its ability to concurrently acquire and analyze various data types in a multimodal and multiscale environment, enabling precise localization of specific areas within samples and enhancing the accuracy and relevance of analyses. This approach showed promise in revealing the metallurgical history of ancient coins. This article focused on composition, microstructure, and manufacturing process of Phoenician-Punic copper-based alloy coins (5th–4th century BCE). The four coins studied by correlative light and electron microscopy, μ-Raman spectroscopy, and X-ray Microscopy exhibited notable differences in elemental composition and microstructures. These variations are attributed to their origin from casting, followed by striking, and subsequent recrystallization due to a more intricate corrosion process.

Archeometallurgical Investigation of a Fragment from a Medieval Sword Blade

A fragment from a medieval sword blade was investigated by metallography, Vickers microhardness tests and slag inclusions analysis are to extract technological information about its manufacturing process. Optical microscopy observations and microhardness measurements indicated that the sword blade was forged via hammer welding, combining different steel bars for an optimal balance of hardness and toughness. A steeling technique involved wrapping a steel bar around a composite billet, crafted by enclosing a hypoeutectoid steel bar around a near-eutectoid steel core. Moreover, it was found that the hardness of the cutting edges was increased with a quenching heat treatment. After quenching, the blade exhibited martensitic microstructure with Vickers microhardness ranging from 500 to 640 HV0.3. The compositional data of a large set of nonmetallic inclusions were collected by scanning electron microscopy coupled with X-ray dispersive spectroscopy. Slag inclusion analysis and multivariate statistics confirmed the blade's composite nature and revealed distinct smelting and forging-related SI groups. Liquidus temperatures indicated smelting temperatures of at least 1156°C for the external section and 1031°C for the internal. The forging temperature was estimated at a minimum of 1143°C. These findings provide insight into the blade’s metallurgical history.

Brass products in the coronet excavated from an M2-numbered Sui-Tang-dynasty tomb situated in Kun Lun Company in Xi'an, Shaanxi

Ancient Chinese brass smelting technology has promoted the invention of zinc smelting, thus becoming an important part of the metallurgical history. However, the information concerning its origin and development is still controversial. In that regard, thorough analysis of composition and structure of the early brass is crucial for studying various stages of the ancient brass smelting technology history. This study aimed to investigate brass artifacts from Kunlun M2 tomb in Xi'an, Shaanxi, dating back during Sui to early Tang Dynasty (581–712 AD). The composition and metallographic characterization of the materials was performed using XRF, SEM–EDS and metallographic analysis. According to the results, brass was composed of 83 wt% of copper, 12 wt% of zinc, and 3 wt% of tin. Furthermore, its microstructure consisted of α-isometric single crystals with some slip lines and a few twinned grains. This indicated that brass was obtained by melting an appropriate mixture of zinc ores and copper ores at a temperature above 920 °C. Furthermore, brass support components were installed on the coronet after integral hot forging and partial cold shaping. Besides, the use of brass in the coronet was in conformity with the social hierarchy of that historical period, and also reflected the attention paid to the properties of materials.

Influence of strain rate on the mechanical response of nanostructured coppers elaborated by SPD and SPS

The influence of strain rate on the mechanical response of two different nanostructured pure coppers was investigated under uniaxial compression. The first nanostructured copper was elaborated by powder metallurgy using the Spark Plasma Sintering (SPS) process. The second nanostructured copper was elaborated by Severe Plastic Deformation (SPD). Conventional characterizations were conducted with quasi-static compression and tensile tests, hardness tests and, with microstructure analysis. The effect of strain rate was evaluated under uniaxial compression at strain rates varying from 10-4 to 10+4 s-1. The high strain rate data were generated with a direct Hopkinson impact technique. The increase of strength with strain rates was analysed and discussed from the Scanning Electron Microscope observations and grain size distribution. The mechanical properties are consequently dependent on the metallurgical history of these samples prepared according to two different routes.

Natural-mixing guided design of refractory high-entropy alloys with as-cast tensile ductility.

Metallic alloys containing multiple principal alloying elements have created a growing interest in exploring the property limits of metals and understanding the underlying physical mechanisms. Refractory high-entropy alloys have drawn particular attention due to their high melting points and excellent softening resistance, which are the two key requirements for high-temperature applications. Their compositional space is immense even after considering cost and recyclability restrictions, providing abundant design opportunities. However, refractory high-entropy alloys often exhibit apparent brittleness and oxidation susceptibility, which remain important challenges for their processing and application. Here, utilizing natural-mixing characteristics among refractory elements, we designed a Ti38V15Nb23Hf24 refractory high-entropy alloy that exhibits >20% tensile ductility in the as-cast state, and physicochemical stability at high temperatures. Exploring the underlying deformation mechanisms across multiple length scales, we observe that a rare β'-phase plays an intriguing role in the mechanical response of this alloy. These results reveal the effectiveness of natural-mixing tendencies in expediting high-entropy alloy discovery.

Fuel selection during long-term ancient iron production in Sudan

ABSTRACTThe Royal City of Meroe, a capital of the ancient Kushite kingdom in modern Sudan, is renowned for its extensive remains of ancient iron production. The exploitation of wood to fuel Meroe’s metallurgical past has long been linked to environmental degradation. However, palaeoenvironmental studies involving archaeobotanical methods such as charcoal analysis, which might confirm or disprove the hypothesis of large-scale deforestation, have so far been missing for the area. Our investigations offer the first comprehensive anthracological data for the iron-smelting contexts at Meroe and its surroundings covering more than 1000 years. They provide unequivocal evidence for extreme selectivity for a single species, the Nile acacia Acacia nilotica (Syn. Vachellia nilotica), throughout the course of the currently known metallurgical history of the Meroe region. The charcoal data neither point to fuel shortage nor to environmental degradation at any point in time during the entire production period. Non-metallurgical contexts show that a wider array of taxa was used for fuel with low values of Acacia nilotica type charcoal. We thus conclude that Acacia nilotica wood was preferably used and mainly spared for the technical application of iron smelting. The probable source areas for Nile acacia wood and possible woody resource management strategies to maintain the fuel supply are discussed.

Phase formation in A3003 alloys

A number of intermetallic compounds can potentially form in the A3003 series of aluminium alloys, such as Al3Fe, Al6Mn, Al2Cu and α-Al15Si2M4, as well as Al9Fe2Si2 and Al8Fe2Si, despite of the low alloying element contents. The phase formation depends on not only the metallurgical history but also the actual alloy composition, as illustrated with Calphad calculations. Considering a specific alloy composition, the phase formation during solidification and consequent heat treatment was discussed. It has been demonstrated that the deviation from equilibrium conditions and the impact of composition segregation can be interpreted with a combination of different types of calculations

Mathematical Characterization of the Tensile Deformation Curve of Cast Iron Materials

The manufacturing process gives cast iron castings properties which are dependent on component design, metallurgy and casting method. Factors as local wall thickness influences the coarseness and type of microstructure and the material will have local properties depending on the local metallurgical and thermal history. The stress/strain behaviour of cast products at load are typically performed by using a tensile test machine.

Numerical and experimental description of the welding residual stress field in tubular joints for fatigue assessment

In order to achieve fatigue resistant welded structures, it is necessary to manage and control welding process-related factors which affect the fatigue strength. These factors are sometimes present as welding defects and sometimes as inevitable residual stresses which are unwanted by-products of welding processes. This subject has been treated in welding research communities since the 1950s. However, the extent of this effect was unclear and is still a matter of debate. Having advanced predictive tools for accurate determining welding residual stresses will not only lead to the possibility of considering precise welding residual stress effects during life estimation but also can be useful to have effective measures for the subsequent mitigation or modification of the welding residual stress fields. The objective of this study is to describe experimentally and numerically the welding residual stress field in welded tubular joints made of structural steel S355J2H in terms of two different case studies. Residual stresses in cylindrical specimens with dummy welds (case-1) and bead on tube welds (case-2) are determined experimentally by means of x-ray, synchrotron, and neutron diffraction techniques. The SYSWELD software is used to calculate the welding residual stresses numerically by integrating the metallurgical transformation effects in order to compute the link between material microstructure and residual stresses. Thermal and metallurgical calculations couple the temperature field and phase proportions by considering the latent heat of fusion/solidification and the transformations in the transient heat conduction equation. Obtained results which include both thermal and metallurgical history are used as input data for mechanical calculations afterward. The accuracy of the both thermal and structural models is validated through experiments for temperature distribution and residual stresses.

Pioneers in Metals Research, Part VI

Abstract The invention of the single crystal jet engine blade under Frank Versnyder and a team of scientists at the Pratt & Whitney Division of United Technologies is considered one of the 50 greatest advances in metallurgical history.

Pb pollution from leaded gasoline in South America in the context of a 2000-year metallurgical history

Exploitation of the extensive polymetallic deposits of the Andean Altiplano in South America since precolonial times has caused substantial emissions of neurotoxic lead (Pb) into the atmosphere; however, its historical significance compared to recent Pb pollution from leaded gasoline is not yet resolved. We present a comprehensive Pb emission history for the last two millennia for South America, based on a continuous, high-resolution, ice core record from Illimani glacier. Illimani is the highest mountain of the eastern Bolivian Andes and is located at the northeastern margin of the Andean Altiplano. The ice core Pb deposition history revealed enhanced Pb enrichment factors (EFs) due to metallurgical processing for silver production during periods of the Tiwanaku/Wari culture (AD 450-950), the Inca empires (AD 1450-1532), colonial times (AD 1532-1900), and tin production at the beginning of the 20th century. After the 1960s, Pb EFs increased by a factor of 3 compared to the emission level from metal production, which we attribute to gasoline-related Pb emissions. Our results show that anthropogenic Pb pollution levels from road traffic in South America exceed those of any historical metallurgy in the last two millennia, even in regions with exceptional high local metallurgical activity.

Environmental legacy of copper metallurgy and Mongol silver smelting recorded in Yunnan Lake sediments.

Geochemical measurements on well-dated sediment cores from Lake Er (Erhai) are used to determine the timing of changes in metal concentrations over 4500 years in Yunnan, a borderland region in southwestern China noted for rich mineral deposits but with inadequately documented metallurgical history. Our findings add new insight into the impacts and environmental legacy of human exploitation of metal resources in Yunnan history. We observe an increase in copper at 1500 BC resulting from atmospheric emissions associated with metallurgy. These data clarify the chronological issues related to links between the onset of Yunnan metallurgy and the advent of bronze technology in adjacent Southeast Asia, subjects that have been debated for nearly half a century. We also observe an increase from 1100 to 1300 AD in a number of heavy metals including lead, silver, zinc, and cadmium from atmospheric emissions associated with silver smelting. Culminating during the rule of the Mongols, known as the Yuan Dynasty (1271-1368 AD), these metal concentrations approach levels three to four times higher than those from industrialized mining activity occurring within the catchment today. Notably, the concentrations of lead approach levels at which harmful effects may be observed in aquatic organisms. The persistence of this lead pollution over time created an environmental legacy that likely contributes to known issues in modern day sediment quality. We demonstrate that historic metallurgical production in Yunnan can cause substantial impacts on the sediment quality of lake systems, similar to other paleolimnological findings around the globe.

Notes on Contributors

Notes on Contributors

Effects of thermal treatments on protein adsorption of Co–Cr–Mo ASTM-F75 alloys

Post-manufacturing thermal treatments are commonly employed in the production of hip replacements to reduce shrinkage voids which can occur in cast components. Several studies have investigated the consequences of these treatments upon the alloy microstructure and tribological properties but none have determined if there are any biological ramifications. In this study the adsorption of proteins from foetal bovine serum (FBS) on three Co-Cr-Mo ASTM-F75 alloy samples with different metallurgical histories, has been studied as a function of protein concentration. Adsorption isotherms have been plotted using the surface concentration of nitrogen as a diagnostic of protein uptake as measured by X-ray photoelectron spectroscopy. The data was a good fit to the Langmuir adsorption isotherm up to the concentration at which critical protein saturation occurred. Differences in protein adsorption on each alloy have been observed. This suggests that development of the tissue/implant interface, although similar, may differ between as-cast (AC) and heat treated samples.

Charles martin hall relative shares pieces of metallurgical history

With chemicals and equipment he fabricated himself or borrowed from his college chemistry professor, Charles Martin Hall changed the world in an Ohio woodshed in 1886. His journey to discover and commercialize the electrolytic process for refining aluminum is the stuff of legend and a testament to how the power of a great idea can overcome limitations in tools, technology, and experience. “Charles Martin Hall fulfilled his life long dream and contributed a nearly unmatched contribution by any other individual patent,” said Gary Tarcy, who discussed Hall’s legacy in his presentation at the Aluminum Plenary Session marking the 125th anniversary of the Hall–Heroult process at the TMS 2011 Annual Meeting on February 28. Providing a connection to Hall—the person behind the process—at the aluminum plenary was the participation of a special guest invited by Tarcy: Emily Phillips, Hall’s great-great niece. Tarcy had met Phillips at the dedication of a historical site commemorating Hall and Frank Fanning Jewett, the chemistry professor who inspired and supported Hall’s early discoveries, at Oberlin College, Ohio, in 2004. When Phillips came across information online about the TMS Hall–Heroult 125th anniversary celebration, she contacted Tarcy with an offer to share a few key pieces from Charles Martin Hall’s life and work. “Emily has some of the earliest aluminum pieces from Hall’s invention,” said Tarcy. “I thought the plenary session attendees would be interested in seeing some of the oldest aluminum metal in the world.” Describing herself as a “family custodian” of Hall’s legacy, Phillips said her interest in Hall’s work was sparked in high school when her grandmother showed her samples from his early experiments that had been passed down through the family. Since that time, Phillips has actively collected information and experiences related to Charles Martin Hall (Figure 1), and her quest has forged connections with the families of many of the people who helped to shape Hall’s life and science. “One of the most interesting aspects of my curiosity about Charles Martin Hall is the people I have been privileged to meet,” said Phillips. “Since the story of his life and discovery is not widely known, it’s been fun to uncover bits and pieces here and there.” Phillips’ research has enabled her to strike up acquaintances with the family of Alfred Hunt, who invested in Hall’s technology to establish the Pittsburgh Reduction Company, the predecessor of Alcoa. She has also lunched in Paris with the grandson of Paul Heroult, who simultaneously and independently developed the electrolysis process and is credited as a co-inventor. She has corresponded with the daughter of Homer Johnson, a close friend of Hall’s and executor of his estate, and has become a familiar face at the Mudd Library at Oberlin and with historians at Alcoa. When visiting the Hall homestead in Ohio, she made a point of climbing the stairs to the cupola “where Charles Martin Hall as a young experimenter almost burned down the house.” Phillips credits Norman C. Craig, professor emeritus of chemistry at Oberlin, as her mentor in trying to uncover these and other small, but interesting, details of Hall’s discovery and the impact of his work. Phillips has presented her collection and stories on more than a few occasions, and was pleased to be a part of the TMS 2011 commemoration of Hall’s discovery. “The fact that we are now celebrating a manufacturing process, which has been improved, but is still basically the same 125 years after its discovery, is very significant,” she said. Despite her dedication to filling the gaps in the historical accounts of Hall’s life, Phillips said one significant mystery remains unsolved—the location of the Perkin Medal, considered the highest honor given in the United States chemical industry, which Hall received in 1911. “I have made inquiries among family members and to Alcoa and Oberlin—no one seems to know where his medal is,” she said. “Perhaps some day, it will turn up!”

Sub-Surface Initiated Rolling Contact Fatigue—Influence of Non-Metallic Inclusions, Processing History, and Operating Conditions

Abstract A number of competing failure mechanisms are involved in bearing failure initiation. For well manufactured bearings operating under clean and well controlled running conditions, sub-surface initiated fatigue is the classical initiation form. Three mechanisms dominate the concept of sub-surface induced initiation and growth: (i) The well documented slow structural breakdown of the steel matrix due to accumulation of fatigue damage in a process superficially similar to tempering, (ii) stress induced generation of butterflies by a process enabling the growth of butterfly micro-cracks and accompanying wings at non-metallic inclusions, and (iii) surface induced hydrogen intrusion causing hydrogen-enhanced fatigue damage accumulation in the matrix. The development of butterflies as a function of contact stress, over-rolling, and non-metallic inclusion characteristics is presented, and the influence of metallurgical cleanliness and processing history on this progression is discussed. The results of laboratory conducted tests are compared to results from field applications where premature spallings have occurred. The progression from butterfly micro-cracks to extending cracks with non-etching borders has been studied. Special interest has been paid to the interaction between the non-metallic inclusion composition and morphology and their propensity to generate butterfly wing formations, as this may affect the way that inclusion harmfulness should be judged in rolling bearing steel quality assurance efforts. Complex oxy-sulfides are the main butterfly initiators in today’s bearing steels.

On Modeling and Simulation of Mechanical Properties of Cast Irons with Different Morphologies of Graphite

Castings are produced by a manufacturing method which gives the components properties that are dependant on design, metallurgy and casting method. The wall thickness influences the resulting coarseness and type of microstructure and the material will have properties dependant on local metallurgical and thermal history. The local properties in a cast iron component can vary essentially in the casting volume, which makes it difficult to optimize the castings with good accuracy. Often simulation of stress/strain of cast products use constant material properties throughout the castings. If the microstructure is determined or predicted at a given point, it is possible to calculate the local material properties and its deformation behavior.

Modelling of the residual state of friction stir welded plates

This paper presents a steady-state simulation of friction stir welding based on a prior computational method developed in [Bastier, A., Maitournam, M.H., Dang Van, K., Roger, F., 2006. Steady state thermomechanical modelling of friction stir welding. Sci. Technol. Weld. Joining 11 (3), 278–288]. This simulation includes two main steps. The first one uses an Eulerian description of the thermomechanical problem: a 3D-mixed Finite Element Model based on a Computational Fluid Dynamics package is used to establish the material flow and the temperature field during the process. In the second step, a steady-state algorithm based on an elastoviscoplastic constitutive law is used to estimate the residual state induced by the process. The steady-state assumption and the original elastoviscoplastic constitutive law are two key features of the present model. This calculation takes into account the whole thermal, metallurgical and mechanical history of the material since the algorithm is based on an integration along the path lines of the particles. The material considered is a 7050 aluminium alloy. It is observed that the longitudinal residual stress field has a two peaks profile: these two peaks are situated in the zone of high gradient of dissolved precipitates fraction. Finally, a parametric study about the influence of welding and rotational speeds is carried out. This parametric study shows that the higher the welding speed and the lower the rotational speed, the lower the temperatures and the lower residual distortions.

Induction heat treatment of a ISO C45 steel bar: Experimental and numerical analysis

An experimental and numerical study of the induction heat treatment applied to ISO C45 steel was carried out. Both normalised and annealed samples were considered. The process parameters were implemented in a numerical code (Sysweld 2000 ®) with an aim of predicting the thermal and metallurgical history of the material. The aim of this work was to create a thermo-metallurgical model of the induction heat treatment validated by experimental results. The experimental results (microstructure and micro-hardness profiles) were compared to the numerical values. A satisfactory agreement was found.

FS02.1 The role of metallurgy in allergic contact dermatitis to metals

The critical factor in determining if an alloy may induce metal sensitisation or elicit allergic contact dermatitis is the release rate of soluble metal ions of allergenic metals at the skin surface. Metals or alloys in direct and prolonged contact with body fluids may result in electrochemical reactions (commonly called corrosion) that release metal ions. Induction or elicitation of metal allergy results if a sufficient amount of metal ions are released and absorbed through the skin where they react with the human immune system. The virtual insolubility of most metals and alloys in aqueous media (including body fluids) limits the bioavailability of metal ions. Several factors influence the rate of corrosion: metal or alloy metallurgical structure, surface films, surface finish, geometry, process history, and composition; body fluid composition, amount, pH, electrolytic properties, dissolved oxygen and other gas content; and the service environment (e.g. temperature, flow rate, etc). A review of recently published studies on metal allergy from a metallurgical perspective provides information that helps explain why certain metals and alloys cause allergic reactions and others (e.g. most stainless steels) do not. This information is useful in predicting what alloys will cause allergic reactions under varying conditions. In order to predict allergic reactions and responses to metals and alloys, metallurgical aspects of ion release should be taken into account. This presentation will increase understanding and interpretation of results of clinical or other scientific studies (e.g. studies in vitro) of reactions and responses to metals and alloys by providing a metallurgical perspective.