Casting Technology

This book presents a new study of Greek large-scale bronze statuary of the late Archaic and Classical periods. It examines the discovery, origin, style, date, artistic attribution, identification, and interpretation of the surviving bronzes, and focuses in particular on their technical features and casting techniques. It contains over 170 plates of photographs and drawings to illustrate its discussion.

It also places the development of the casting techniques in connection with the stylistic evolution in Greek free-standing sculpture. During the Classical period, artists preferred bronze to marble when creating their contrapposto figures. Indisputably, bronze gave particular freedom to artists in creating three-dimensional figures. In addition, the evolution in style encouraged the development of the uses of bronze to serve the new needs and tendencies in sculpture during the late Archaic and especially the Classical period. Through the examination of how technical matters affect style, this book presents fresh interpretations of these important monuments of Greek art and offers a new approach in the field of Greek free-standing bronze sculpture.

Aufgrund der archäometrischen Untersuchungen besteht kaum Zweifel daran, dass die aus Kalkstein gefertigten Dauergießformen aus Magdeburg zum direkten Gießen von Zinnobjekten bzw. Gegenständen aus Zinnlegierungen oder Blei benutzt wurden. Eine andere Verwendung kommt – mit Ausnahme der Herstellung von Wachsmodellen – angesichts der Temperaturempfindlichkeit des Kalksteins nicht infrage. Es liegt deshalb auf der Hand, mittelalterlichen Kalksteinformen generell eine derartige Verwendung zu unterstellen. Allerdings wurden in der Vergangenheit die wenigsten Fundstücke von anderen Fundorten diesbezüglich analytisch untersucht, sodass nur eine geringe Anzahl von gesicherten Belegen für die genaue Benutzung von Dauerformen aus Kalkstein bzw. aus anderen Materialien vorliegt. Im Folgenden wird das aus Europa stammende Fundmaterial überblicksweise vorgestellt und – soweit anhand von Literaturangaben möglich – hinsichtlich der Verwendung bewertet. Der Fokus liegt v. a. auf chronologisch nahestehenden Vergleichsfunden zu den Magdeburger Gießformen. Daneben werden Weißmetallobjekte besprochen, die in ihrer Machart in vergleichbaren Gießformen entstanden sind.

The paradoxographer Philo of Byzantium (De septem mundi miraculis 4) claimed that the Colossus of Rhodes was cast in situ in horizontal courses buried gradually by an earthen embankment. The study of large-scale ancient bronzes and foundries, however, has provided evidence only for casting in large sections. Here it is argued that the technology used for the Colossus was no exception.
How do we reconstruct the fabrication process of an exceptionally large and lost statue? First, the general parameters for the working steps must be known. Therefore, the indirect lost-wax process in antiquity is compared with better-known methods used to create two extant colossal statues, the Great Buddha in Nara (cast in courses) and the Bavaria in Munich (cast in large sections). Then the various steps of the working process attested in ancient times are examined. The analysis reveals basic di∂erences between the three casting methods.
Philo’s text contains a certain level of technical knowledge but lacks important details and indeed states an important falsehood. A possible explanation for this discrepancy is that he used a written reconstruction of a working process. This means that we can give the archaeological evidence greater weight than this text.

The digital publication is available under this links:
http://www.getty.edu/publications/artistryinbronze/large-scale-bronzes/2-vedder
in: /http://www.getty.edu/publications/artistryinbronze.
Other formats include a pdf, which is downloadable for free: http://www.getty.edu/publications/artistryinbronze/downloads/DaehnerLapatinSpinelli_ArtistryinBronze.pdf

El trabajo de los metales Los metales son apreciados por los humanos a causa de la gama de propiedades que presentan, y que les proporcionan un valor simbólico, estético y práctico. La posibilidad de dar forma a los objetos de metal a voluntad es, tal vez, su cualidad más importante. En tiempos prehispánicos se utilizaron principalmente el cobre, puro o aleado con estaño, arsénico o plomo, y el oro y sus aleaciones-por ejemplo, la tumbaga, que es una combinación de oro, plata y cobre. Aún en la actualidad se emplean las dos maneras de traba-jo básicas con este material: a) Por martillado, tratando el metal como sólido y deformándolo a golpes hasta alcanzar la forma deseada, por ejemplo, una lámina; en los metales trabajados más antiguos de América se usó esta técnica. b) Por vaciado, utilizando el metal fundido en su forma líquida. La fundición a la cera perdida es una compleja técnica metalúrgica que permite gran libertad en el diseño de las formas que se quieren crear. Fue utilizada en el mundo prehispánico para crear objetos, principalmente ornamentales, que todavía hoy impresionan por su diseño y la consumada aplicación de la técnica.

"Of the approximately 500 different stone moulds which came out of a high medieval goldsmiths from Magdeburg/Germany, 45 pieces could be examined in detail. The primary goal of the archaeometallurgical and experimental archaeological examinations was to determine the use of the moulds as well as the sort and provenance of the rock material used. Therefore it was possible to extract wedge and powder samples of the rock as well as remains of metal. Moreover all moulds had to be checked with regard to traces of use. Additionally casting and glowing tests were carried out with the potential mould material to study its behaviour under different casting and temperature conditions.
The petrographical examination of thin sections from 15 stone samples with transmitted- and direct-light microscopy and the examination of rock powders has shown the use of a fine-grained Jurassic and/or Cretaceous marly limestone. For it the so called »Plänerkalkstein« of the northern foothills of the Harz Mountains is most probable. But also the »Solnhofener limestone« of the southern part of the Franconian Jura has to be considered.
Because there are no discolorations within the pouring system of all moulds it is clear that they cannot have served for the founding of bronze, gold and silver, which is confirmed by the results of the casting experiments. With energy dispersive X-Ray fluorescence analysis, light and scanning electron microscopy it could be shown reliably that 23 metal specimens of the cast system and several registration holes were made of pewter. Sometimes small amounts of copper might have been added to these tin-lead alloys. Because metal residues were available in the cast system at only six moulds, you cannot conclude on the general use of these metals for all of the 500 moulds. With discolorations outside the cast system and bright, powder like coatings on the complete surface at 60 % of all moulds an indirect reference to their use is given. Both observations indicate a heating of the whole mould. This is reinforced by scanning electron microscopic examination of thin sections and diffraction analysis of powder samples which revealed the »burned« character of the coating. Glowing tests with the Plänerkalkstein and Solnhofener limestone demonstrated that discolorations arise from 300 °C upwards, however, decomposition of calcium carbonate starts at around 700 °C. Thus all moulds with a bright surface coating must have been heated at temperatures of at least 700 °C. Such a measure can only be explained plausibly in connection with the metal cast and furthermore with the casting of pewter under consideration of the missing discolorations in the cast system. According to the results of the casting experiments it is quite improbable that the moulds had been heated at high temperatures like 700 °C before their use. However, a general explanation for the motives of a possible heating after founding cannot be given with the performed examinations. So some questions are still unanswered."

A Byzantine Casting Mould for a Hystera (Womb) Amulet and a Cross in the Museum Schnütgen, Cologne: A Contribution to the Cultural and Religious History of Byzantium and the Material Culture of Byzantine Magic, in: Lebenswelten zwischen Archäologie und Geschichte. Festschrift für Falko Daim zu seinem 65. Geburtstag. RGZM Monographien 150, hg. von J. Drauschke, E. Kislinger, K. Kühtreiber, T. Kühtreiber, G. Scharrer-Liška, T. Vida, Mainz 2018, 629-644.


A Byzantine casting mould in Cologne comprises cavities for eight pendants, amongst them a pendant cross and a »pagan« hystera amulet with a womb demon made to protect the ability of procreation. The context and provenance of the mould are unknown, but comparisons suggest a date in the 12th-14th centuries. However, since hystera amulets are usually dated earlier, to the 10th-12th centuries, the mould thus represents the latest material evidence for hystera amulets in Byzantium. This demonstrates the continued use of »pagan« amulets, predominantly known through literary evidence. Throughout Byzantine history, amulet wearing had been fervently fought by the church, but also by the state since Constantine the Great. Amulet making was then explicitly prohibited in the 8th-century Ecloga. Nevertheless, this mould also served to cast a Christian cross in the same workshop, thus making it a unique and fascinating object, which provides a revealing insight into the cultural and religious history of Byzantium.

— Porosity is the one of the defects most frequently encountered in ductile iron casting. Porosity formation cause costly scrap loss and limits the use of cast parts in critical high strength applications. The amount of porosity is closely related to sand casting processes parameters. A considerable reduction in porosity formation can be obtained using optimization technique in the sand casting process. Casting is a manufacturing process to make complex shapes of metal materials in mass production may experience many different defects such as gas porosity, pin holes, blow holes, shrinkages and incomplete filling. The Gating/riser system design play very important role for improving casting quality. Due to the lack of scientific procedures the design process is normally carried on a trial-and-error basis. The main objective of this paper is to redesign the components using Auto-CAST X1 simulation software and increases the product life. Many researchers reported that 90% of the defects in casting are obtained only because of wrong design of gating and feeding system and only 10% due to manufacturing problems. In this paper to study the solidification behavior of material, detection of hot spots, blow holes and removed such defects in the casting with the help of mentioned casting simulation software. The simulated results also compared with experimental results.

The Nahal Mishmar hoard was discovered in 1962 in a cave, inside a pit, which was covered by a large rock. The pit was close to the entrance of the cave. This cave saw activity during early periods, predating the Iron Age, as well as during the Roman period and therefore cannot be considered a single period site. This paper proposes that the hoard, being a cache, contains items of various periods. It is impossible to determine the nature of activity, which evolved in this cave during a period of six thousand years. It should also be noted that the items were not discovered in a clearly defined strata.

Krank kasnağı içten yanmalı motorlarda krank milinde meydana gelen burulma titreşimlerini azaltmak için kullanılan bir ayarlı kütle sönümleyicidir. Krank kasnağı komponentleri iyi işlenebilirlik, iyi yüzey kalitesi, yüksek mukavemet, aşınma direnci, ses ve titreşim sönümleme yetenekleri nedeniyle üretiminde sfero malzeme tercih edilmektedir. Otomotiv sektörünün maliyetleri azaltma çalışmalarının artması neticesinde üretim yöntemlerinin bilgisayarlı üretim teknikleri ile desteklenmesi, simülasyon programları ile hatalarının optimizasyonu ve maliyet azaltma çalışmalarında önemli bir yere sahiptir. Bu çalışmada tasarlanan model ile boşluklar oluştuğu tespit edilen döküm ürünler ve döküm parametrelerinin simülasyon programına birebir eklenmesi amaçlanmıştır. Altair Inspire Cast simülasyon programı ile modellemelerin analizleri gerçekleştirilmiştir. Üretilen döküm numunelerinden alınan sonuçlar ile döküm simülasyon programındaki sonuçlar karşılaştırılmıştır. Analiz sonuçları incelenerek döküm anında yaşan problemler için çözümler gerçekleştirilmiştir. Çalışmada kumla döküm, modelleme, metalografi görüntüleme teknikleri kullanılmış ve sonuçlar tartışılmıştır.

Gießformen sind nicht nur von einem realienkundlichen und kunsthistorischen Standpunkt aus gesehen von großer Bedeutung, sie stellen auch für die archäometallurgische Forschung wichtige Zeugen des Metallhandwerks zu unterschiedlichen Zeitepochen dar. Aus ihnen lassen sich unter anderem unmittelbar Aussagen zur Herstellungstechnik von Gegenständen und den zugrunde liegenden Gießtechnologien ableiten, die anhand der fertigen Metallprodukte nicht immer möglich sind. Hierbei spielt es keine Rolle, ob es sich um verlorene Formen oder um Dauerformen handelt. Wenn man sich jedoch vergegenwärtigt, dass Gießformen im archäologischen Fundbild gegenüber Fertigprodukten einen verschwindend geringen Anteil ausmachen, wird verständlich, wie oft man auf Rückschlüsse aus den Metallobjekten selbst angewiesen ist. Aus diesem Grund und unter dem Gesichtspunkt, dass anderenorts häufig nur einzelne Gießformen angetroffen wurden, kann der Magdeburger Fundkomplex mit seinen annähernd 800 steinernen Einzelfundstücken als einzigartiger Glücksfall angesehen werden. Im Umfang am besten vergleichbar sind höchstens die Funde tausender Lehmgießformfragmente von der Insel Helgö, Stockholms län (Schweden), und aus der Altstadt Lübecks, Schleswig-Holstein, sowie mehrere Funde von hunderten Steingießformen aus Serensk, Pskow und Weliki Nowgorod, alle Russland, sowie Kiew, Ukraine. Zudem liegen recht umfangreiche Funde mit 260 und 47 Gießformen aus dem französischen Mont-Saint-Michel und dem tschechischen Kutná Hora vor.

Der Stellenwert des Magdeburger Komplexes ist aber nicht allein an seiner immensen Fülle zu bemessen. Große Bedeutung besitzt der Fund von steinernen Dauerformen v. a., weil er auf gießereitechnischer und metallurgischer Seite eine Reihe neuer, bisher ungeahnter Einblicke in das hochmittelalterliche Gießereiwesen erlaubt. Außerdem ist die potenzielle Verwendung der Gießformen zur Herstellung von Zinnobjekten bemerkenswert, die in dieser Intensität einmalig wäre und die mittelalterliche Handwerkskultur der Zinngießer – nicht nur derjenigen in Magdeburg – in einem völlig neuen Licht erscheinen lassen würde.

Im Gegensatz zum vorangegangenen Kapitel stehen im Folgenden vorwiegend die gießtechnischen und archäometallurgischen Aspekte der Gießformen im Vordergrund. Dafür war es nicht nur möglich, die Formen eingehend mikroskopisch hinsichtlich der Gesteinsart und auf Gebrauchsspuren hin zu prüfen, sondern auch Metallreste und Gesteinsproben von zahlreichen Exemplaren mit naturwissenschaftlichen Analyseverfahren zu untersuchen. Darüber hinaus wurden Gießversuche mit Vergleichsgestein in die Betrachtungen einbezogen. Diese spezielle Kombination erlaubt es, ein bisher beispielloses, konkretes Verständnis von der Funktion und Geschichte der Gießformen zu erhalten. Bevor jedoch auf die Ergebnisse der naturwissenschaftlichen Untersuchungen eingegangen wird, werden in Ergänzung zu den Darlegungen von G. Ditmar-Trauth (siehe Kap. Der Magdeburger Gießformenfund) zunächst noch einmal technische Kriterien herausgestellt und vertiefend erläutert.

"For full text, follow this link

http://www.4shared.com/office/xMfc6v9yce/1990_the_effect_of_casting_par.html

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Al-5 % Sr master alloy is used as a modifier for a commercial hypoeutectic Al-Si alloy. The effect of casting parameters such as molten metal temperature and holding time in the molten state after Sr addition on the degree of modification is examined. Molten metal temperatures up to 1123 Kand holding time up to t h are tried. The relation between the microstructure and tensile properties are discussed. Optimum tensile properties are obtained with modified specimens cast in steel mould after a holding time of 5 min. Higher degrees of modification give higher volume fractions of Al solid solution. An intergranular mode of fracture is observed under all conditions due to excess Pb in the alloy."

We introduce a new experimental approach to the compositional and thermo-mechanical design and rapid maturation of bulk structural materials. This method, termed rapid alloy prototyping (RAP), is based on semi-continuous high throughput bulk casting, rolling, heat treatment and sample preparation techniques. 45 Material conditions, i.e. 5 alloys with systematically varied compositions, each modified by 9 different ageing treatments, were produced and investigated within 35 h. This accelerated screening of the tensile, hardness and microstructural properties as a function of chemical and thermo-mechanical parameters allows the highly efficient and knowledge-based design of bulk structural alloys. The efficiency of the approach was demonstrated on a group of Fe–30Mn–1.2C–xAl steels which exhibit a wide spectrum of structural and mechanical characteristics, depending on the respective Al concentration. High amounts of Al addition (>8 wt.%) resulted in pronounced strengthening, while low concentrations (<2 wt.%) led to embrittlement of the material during ageing.

Shrinkage porosity and metal expansion penetration are two casting defects that appear frequently during the production of complex-shaped lamellar graphite iron components. These casting defects are formed during the solidification and usually form in the part of the casting which solidifies last. The position of the area that solidifies last is dependent on the thermal conditions. Test castings with thermal conditions like those existing in a complex-shaped casting were successfully applied to provoke a shrinkage porosity defect and a metal expansion penetration defect. The investigation of the primary dendrite morphology in the defected positions indicates a maximum intradendritic space, where the shrinkage porosity and metal expansion penetration defects appear. Moving away from the defect formation area, the intradendritic space decreases. A comparison of the intradendritic space with the simulated local solidification times indicates a strong relationship, which can be explained by the dynamic coarsening process. More specifically, long local solidification times facilitates the formation of a locally coarsened austenite morphology. This, in turn, enables the formation of a shrinkage porosity or a metal expansion penetration.

ABSTRACT: The manufacturing technology of large size shells (steel - bronze - babbit) for diesel engines and compressors is developed. According to it covers from lead bronze powders are molded in layers on an internal surface of a steel blank by the centrifugal method, and heating are made up to a powder sintering temperature. For industrial use of the technology three manufacturing schemes of shell halves are offered. There are shown advantages and defects of the developed technological schemes in this work. Bimetallic blanks machining features are also considered.

KEYWORDS: shells, bronze sintered covers, machining, different cover thickness, centrifugal forming.

CONCLUSIONS: The manufacturing technology of large size shells (steel - bronze - babbit) for diesel engines and compressors based on centrifugal molding in layers of bronze cover and its plotting in the sintering mode is developed. In the article three schemes of shells manufacturing are offered for industrial use of this technology. Advantages and defects of the schemes use were analyzed.
The expressions for a cover absolute different thickness definition, for cover material consumption increase definition, values of internal and outside radiuses of a steel bar are obtained depending on sizes of the ready shells, minimum cover height and parameters of machining.
There was shown that when manufacturing two halves of a shell from one cylindrical blank in order to decrease a cover material consumption and a labor intensity of machining it is necessary to provide the minimum longitudinal cut width of a bimetallic blank.

Proceedings of 6th International conference “CO-MAT- TEC’98”- Trnava,1998.- P.439-445.

This article is based on the conclusions I drew on the casting technique of the bronze Antikythera ephebe in my MRes and my PhD theses: Dafas, K. A., 2008. Ο Χάλκινος Έφηβος των Αντικυθήρων, Master’s Thesis, Aristotle University of Thessaloniki (Thessaloniki) 45-56 and Dafas, K. A., 2013. Greek Large-Scale Bronze Statuary Revisited: The Late Archaic and Classical Periods, PhD Thesis, King’s College London, University of London (London) 103-109, respectively.

This article discusses the technical features and the casting technique of the so-called Antikythera ephebe, a bronze statue found in the sea off the small island of Antikythera in the beginning of the twentieth century. While the discovery, style, date, artistic attribution and identification of the statue have been discussed previously in scholarship, a number of problematic issues still remain to be resolved, the most important of which is the casting technique. Through scrutiny of the technical features of the statue, this article sheds light on the exact casting method used for its production, thus, contributing to our better understanding of contemporary casting techniques used in Greek monumental bronze statuary during the late Classical period.

ln this study, the effects of different melt cleaning fluxes on the inclusion content and tensile properties of an aluminum casting alloy were compared. Melt treatments, consisting of rotary degassing with N2 gas, and flux addition were executed using four different fluxes. The inclusion content of the melts was investigated with the evaluation of K-mold samples. ln order to get information about the impact of the differences of melt quality on the mechanical properties of final products, cylindrical tensile specimens were machined from heat-treated castings and tensile tests were carried out. The fracture surfaces of tensile specimens and K-mold samples were inspected with stereomicroscope and scanning electron microscope.