Lost-wax Research Articles

Almost the same, but not quite: an analysis of Late Bronze Age swords in the Balearic Islands

In the present work we carry out a study of all the Late Bronze Age swords recorded in the Balearic Islands. They represent a set of local practices and traditions alongside foreign ideas and archetypes. To carry out the study, we employ a strategy that joins technological and archaeometric analyses with approaches that consider isotopes and typologies. Of note among the data considered is the importance of metal coming from deposits in Linares, followed by Menorca and Mallorca, and finally, more marginally, Sardinia. A technological analysis of the manufacturing processes provides evidence, in a local context, of the use of the lost-wax casting technique, compound objects, and ternary bronzes, all technologies foreign to the Balearic Islands. Finally, we reflect on the local practices in which these objects were embroiled. All of this allows us to provide an in-depth examination of the interaction networks as well as the changes that took place in local metallurgical practices as the result of the circulation of ideas and knowledge.

Impact of Digital Manufacturing Methods on the Accuracy of Ceramic Crowns.

The purpose of this study was to assess the accuracy of full coverage crowns produced by two manufacturing methods: additive 3D printing and subtractive milling utilizing three different predefined cement spaces. Six groups were allocated based on the manufacturing method and the predefined cement space: printed wax with a 20 µm space (PW1); printed wax with a 50 µm space (PW2); printed wax with a 100 µm space (PW3); milled wax with a 20 µm cement space (MW1); milled wax with a 50 µm cement space (MW2); milled wax with a 100 µm cement space (MW3); milled zirconia coping with a 20 µm cement space (MZ1); milled zirconia coping with a 50 µm cement space (MZ2); milled zirconia with a 100 µm cement space (MZ3). All fabricated specimens were scanned using an Identica Blue 3D scanner and saved as standard tessellation language (STL) files. A triple scan method was performed using 3-matic software to assess accuracy. The discrepancy values were recorded in micrometers, and the analysis was conducted using one-way ANOVA. The wax printing method, with a cement gap design of 100 μm, demonstrated a significant improvement in the accuracy compared to the other methods (P<.01). In contrast, the zirconia milling method exhibited significantly lower accuracy relative to the other techniques (P<0.01). Moreover, different cement spaces resulted in various accuracy levels but the only statistically significant difference was observed for the 100 µm cement space in the printed wax group. The additive 3D printing method exhibited greater accuracy than the subtractive milling approach. Furthermore, altering the cement gap was found to impact the accuracy of both techniques, albeit without statistical significance. The accuracy of each CAM technique was investigated in this study, highlighting the promising accuracy of 3D-printed patterns for the lost-wax technique over direct crown milling. However, all methods produced reliable and accurate crown restorations.

Research Progress of Bronze Ware Ornamentation in the Shang Dynasty of China

Bronze ware is an important representative of ancient Chinese culture, and the Shang Dynasty is the peak of China’s bronze casting technology. As an important symbol of ancient culture, the bronze ornaments of Shang Dynasty in China. Deeply reflect the religious belief, social structure and cultural value at that time. Through a systematic literature review of the origin, classification and evolution of the bronze ornament, this paper aims to deepen the understanding of the Shang Dynasty bronzes and their cultural connotation. Among the existing studies, the current research on Shang Dynasty bronze ornament mainly focuses on the categorization of ornament, its relationship with culture and the evolution rules. Specifically, the classification of bronze ornament is diverse and represents the different symbolic meanings. Shang Dynasty bronze ornaments are closely related to religious beliefs and social structures, and evolved over time. In general, these studies have enriched the cultural knowledge of Shang Dynasty bronzes, while some rare ornaments have been understudied and the research methods need to be further innovated. The significance of this study is clear: by examining Shang dynasty bronze ornament, it can increase people’s understanding of ancient Chinese religious culture and feudal social structure, and also contribute to the identification and conservation of modern bronzes. Future research can apply modern scientific and technological tools to further reveal the deeper connotations and historical value of Shang culture.

Application of X-Ray Computed Tomography to Identify Defects in Lost Wax Ceramic Moulds for Precision Casting of Turbine Blades.

This article presents the results of testing the suitability of X-ray computed tomography for the quality control of the casting moulds used for producing turbine blades. The research was focused on the analysis of cross-sectional images, spatial models and the porosity of moulds using a Phoenix L 450 microtomograph. The research material consisted of samples from three mixtures of ceramic materials and binders intended for producing casting moulds using the lost wax method. Various configurations of filling materials (Molochite and quartz flours) and binder (Remasol, Ludox PX 30 and hydrolysed ethyl silicate) mixtures were considered. X-ray computed tomography enabled the detection of a number of defects in the ceramic mass related to the distribution of mass components, porosity concentration and defects resulting from the specificity of the mould production. It was found that casting mould quality control on cross-sectional tomographic images is faster and as accurate as the analysis of three-dimensional models and allows for the detection of a whole range of ceramic defects, but the usefulness of the images is greatest only when the cross-sections are taken at an appropriate angle relative to the object being examined.

Beyond linear narratives: Complex copper ore exploitation strategies in Early Bronze Age China revealed by geochemical characterization of smelting remains

Despite decades of efforts to reconstruct the bronze production and metal distribution systems of the Shang period in Bronze Age China, there remains limited understanding of the ore choices and smelting practices of the Shang people. This study addresses this research gap by conducting a detailed investigation of Shang period copper ores and smelting remains uncovered at the Tongling site in the Middle Yangtze River valley. The results of lead isotope, copper isotope, trace element, and rare earth element (REE) pattern help to classify the slags from this site into two groups, associated with smelting sulphidic (Group A) and oxidic (Group B) copper ores, respectively. This finding not only serves as the first physical evidence of the use of sulphidic copper ores in Early Bronze Age China but also provides pivotal details of the copper resource exploitation strategies of the Shang people. It challenges the traditional narrative that the Shang people moved to this area solely for the high-grade supergene deposits. The parallel use of both supergene and hypogene ores at the same site complicates the notion of a linear, technological evolution from simpler to more advanced copper sources. Despite the presence of hypogene ores, the study reveals that the Shang people maintained labour-intensive smelting practices, including crushing slag to recover trapped metallic prills, to meet the demands of large-scale bronze casting. This nuanced approach to copper resource exploitation reflects a complex, context-dependent strategy rather than a technological revolution. By highlighting these intricate metallurgical choices, this research contributes to a broader rethinking of early technological development, underscoring the diversity and adaptability of ancient craft industries and their role in shaping Shang society.

Bronze casting in Late Antiquity in the Marche Region

This essay reviews the discovery of three sites where deposits of bronze fragments have been found, in the Roman cities of Pisaurum, Sentinum and Potentia. Each site yielded small bronze fragments and some tools, which lead us to suppose that these were sites of Late Antique foundries, where large bronze statues and other bronze objects were broken up to be remelted. The foundries were located on land previously occupied by taverns in the forum area or by residential quarters. This means that the urban plan of the cities had already been partially transformed, probably due to Christianisation and the construction of churches, which became the new community centres, to the detriment of the older areas of the forum. The rampant poverty and shortage of raw materials, especially metals, made foundries indispensable and, consequently, their widespread presence, even within the cities, probably became customary. Perhaps the numerous bronze fragments found in other centres of the region should also be interpreted in this same sense, as indications of foundries, even if the structures where the metal was worked have not been preserved.

Technical examination, elemental analysis and conservation of the arm of a colossal bronze statue from Aegion at the conservation laboratories of the National Archaeological Museum at Athens

The bronze arm, belonging to a colossal statue (presented by A. G. Vordos in this volume), was examined at the Chemical-Physical Research &amp; Archaeometry Laboratory of the National Archaeological Museum (NAM) in Athens. According to prevailing methodology the examination comprised: macroscopic, microscopic and endoscopic examination, elemental analysis p-XRF, X-ray radiography, recording of ancient repairs. It is assumed that the arm was manufactured by the indirect lost wax casting technique and was found to contain an enormous amount of lead (av. 40.15 %), a fact that dates it to the late Hellenistic or Roman period. The arm was consequently conserved at the Metal Conservation Laboratory of the NAM and it has now been returned to the Ephorate of Antiquities of Achaia in Patras

New research on the Cleveland Apollo

This paper presents new technical details on the original manufacture and modern reconstruction of the Cleveland Apollo, a nearly life-size ancient bronze sculpture of the youthful god acquired by the Cleveland Museum of Art in 2004. Although previous studies had shown the sculpture to be an indirect lost-wax casting, few joins had been discussed in detail. Recent, more comprehensive radiographs, combined with extensive external and internal visual analysis, now permit a more thorough explanation of the assembly, from work on wax models through casting (in at least six sections), patching, and finishing, as well as post-manufacture damage. Together with radiography, analysis of numerous and varied modern restoration materials provides a fuller picture of the way the object was more recently re-assembled. A new digital 3D model of the sculpture, now available, will be essential for future study, interpretation, and display.

Occurrence and Contamination Levels of Polychlorinated Dibenzo-P-Dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) in Soil and Sediment in the Vicinity of Recycled Metal Casting Villages: A Case Study in Vietnam

ABSTRACT This study aims to identify the occurrence and characteristics of PCDD/Fs in soil and sediment samples from secondary copper and aluminum villages in northern Vietnam using the HRGC/MS system. Additionally, it assesses the impact of PCDD/Fs on human health and the potential ecological risks they pose. The residual concentrations of PCDD/Fs in soil and sediment samples collected from the secondary copper Dai Bai village and secondary aluminum Man Xa village were as follows: 0.37 ± 0.29 ng TEQ/kg d.w. (ranging from 0.06 to 0.63 ng TEQ/kg d.w.); 4.88 ± 0.51 ng TEQ/kg d.w. (ranging from 0.512 to 12.17 ng TEQ/kg d.w.); 11.2 ± 5.31 ng TEQ/kg d.w. (ranging from 5.12 to 15.2 ng TEQ/kg d.w.); and 21 ± 12.7 ng TEQ/kg d.w. (ranging from 0.37 to 31.6 ng TEQ/kg d.w.), respectively. The distribution of PCDD/Fs indicated Octa- and Hepta-CDD/Fs as the dominant congeners with high chlorine content. The TEQ levels of PCDD/Fs in all soil and sediment samples were found to be below the allowable limit according to Vietnamese regulations, with the top contributor being 2,3,4,7,8-PeCDF. Samples collected near the production areas exhibited higher levels of PCDD/Fs compared to those collected farther away. The UNEP toolkit was utilized to determine the permissible dioxin TEQ concentrations suitable for livestock farming. The lifetime average daily doses (LADD) of PCDD/Fs via soil ingestion in Man Xa and Dai Bai were calculated as 0.04 × 10−3 and 1.54 × 10−3 pg TEQ/kg d.w. respectively. The relative cancer risks for humans were estimated at 0.05 × 10−12 and 2.05 × 10−12. Furthermore, the ecological risk assessment method indicates that dioxin in all soil and sediment samples near the aluminum recycling craft village had a negative impact on the ecosystem. In contrast, sediment samples taken away from the aluminum recycling craft village and all sediment soil samples in the bronze casting village did not show negative impacts on the ecosystem.

FOUNDRY TRIBOTECHNICAL BRONZE BrO3A3 CORROSION RESISTANCE INVESTIGATION

Problem statement. Bronzes have been and remain the main material for friction bearings, anti-friction and corrosion-resistant parts manufacturing that work under high loads, chemically active aggression influence at low and elevated temperatures, in cavitation, erosion, etc. conditions. That is, technology continuous development requires from anti-friction bronzes constant their corrosion resistance increasing, as a factor that will allow to significantly expand their application scope and increase cast products from them durability and reliability. The purpose of the articles. Based on relationship between corrosion damages and chemical composition analysis, compare BrO3A3 bronze corrosion resistance with BrA5, BrA9Zh3L and BrO5Tz5C5 bronzes corrosion resistance as the materials most often used in industry for parts manufacturing that work in friction nodes and chemically active environments. Methodology. Alloys for samples production have been prepared by technical purity primary charge materials fusing. Melting has been carried out in induction crucible furnace using a graphite crucible and charcoal as a coating material. Cast bronze samples corrosion resistance studies have been carried out in accordance with ISO 7384:2001, ISO 11845:1995 and GOST 9.308-85 requirements. Studied samples corrosion resistance has been evaluated based on the results of their relative weight loss during exposure for 90 days in climate chamber at relative humidity of 93 ± 3 % and temperature of 40 ± 2 °С, in sea and fresh water with temperature of 20...22 °С. Conclusions. BrO3A3 bronze, among the studied foundry bronzes, is characterized by the best level of anti-corrosion properties in all environments used in this research. In this regard, it is a reason to recommend the studied bronze for tribotechnical purpose cast parts manufacturing, which work in air, fresh or sea water.

Casting and Forging techniques Found in Bronze vessels Excavated from Mangduksa Temple Site in Gyeongju

Metallographic analysis of microstructure, chemical composition and hardness was carried out on 7 bronze vessels from Mangduksa temple site in Gyeongju. Result show that the technology of bronze vessels divided into casting and forging followed by quenching. Tin contents of casting bronzes were around 11∼14 wt%, forging bronzes were about 21∼23 wt% tin. Kundika and dish of casting bronzes were Cu-Sn-Pb alloys and 5 bowl samples were produced using Cu-Sn binary alloy materials. These show that the manufacturing technology was applied different depends on the Sn contents. Also 4 bowls of approximately 20 wt% tin were manufactured by forging and quenching at above 520℃ avoid formation of the brittle δ phase. The non-metallic inclusions in the 7 bronze samples are divided into Cu-S and Cu-Fe-S-Se systems, indicating that the copper ore used the production is different. It was confirmed that casting bronze vessels had lower micro-hardness values than forging samples, and that hardness values changed depending on Sn content and processing.

Features of using SLA‑technology in the manufacture of molds for lost wax casting

The results of using SLA‑technology in the manufacture of molds for obtaining wax models in lost wax casting are presented. 3D printing modes of molds have been developed to ensure the required roughness of the working surfaces and durability of the resulting molds. The optimal parameters for pressing the wax composition into molds made using SLA technology have been established. It is shown that the use of SLA technology for the manufacture of molds makes it possible to obtain wax models and castings of the required quality. An experimental technology has been developed for the production of castings from bronze by casting according to smelted models.

In-house dental lab-based cranial prosthesis fabrication: a technical note.

Cranial prostheses are frequently required for patients with cranial defects secondary to trauma, decompressive craniectomy, or other pathologies. When the resected or craniotomized bone cannot be reused, cranioplasty with artificial materials offers both aesthetic and protective benefits. However, high-end custom-made options, like polyether ether ketone or titanium prostheses, are expensive and not widely available. Heat-cured polymethyl methacrylate (PMMA) prostheses are generally preferred over their cold-cured counterparts. In-house dental laboratories can provide a cost-effective and practical solution by employing a lost-wax technique akin to denture fabrication, utilizing a three-dimensional printed custom open mold. Fabricating large heatcured PMMA cranioplasts presents certain challenges, such as the need for large flasks and potential porosity. These can be overcome by using a large stainless steel container (a tiffin box) and M-Seal epoxy to ensure an airtight curing process. This method can be easily adopted by standard dental laboratories. At our center, four patients have successfully fitted with cranioplasty prostheses produced using this technique. Even though the patients are outside of the scope of this technical note all of them indicated high satisfaction, and no complications were reported. This straightforward approach demonstrates that in-house, heat-cured PMMA cranioplasts can represent a viable, cost-effective option for cranial reconstruction.

Documentation of Telangana Intangible Cultural Heritage to Promote creative Economy for Sustainable Development

UNESCO 2003 Convention paved way for Safeguarding of Intangible Cultural Heritage (ICH). It defines the ICH as practices, representations, expressions as well as knowledge and skills. Oral traditions and expressions include performing arts, social practices, rituals and festive events, Knowledge and practices concerning nature, universe, and Traditional Craftsmanship. The main problem of Indian society is that the highly skilled persons are one side without Education and highly qualified academicians, technicians on the other hand have no skills. The unorganized employs acquire the skills on their own. Proper training is needed for skill enhancement and social commitment to involve them in curriculum and community development. The Telangana Region is renowned for its exceptional ICH-like weaving and dyeing techniques. The notable Telangana sarees include Pochampally Sarees and Gadwal Sarees. Festivals like Bonalu, Bathukamma, Dasara, and Peerilu are unique to Telangana Region. Telangana is famous for its bronze Castings that require exquisite skills to create incredible idols. Telangana handicrafts are Cheriyal Scroll Paintings, Batik Paintings, and Nirmal Paintings, metalware and wooden crafts. Home linen includes handlooms such as Banjara Needlecrafts and Gadwal Handloom. Hyderabad is famous for Lac bangles, jingle on pearl strings. There is a great scope for Entrepreneurship Development in Intangible Cultural Heritage and its allied sectors in Telangana State. Pottery, Silver Filigree, Basket-Mat Making, Toy Making, Saree Designs will provide very big market and solve the unemployment problems. In addition to Documentation and Safeguarding the endangered cultural expressions create opportunities for an internship with industry, business, artists, and craftsmen.

Applying a mask R-CNN machine learning algorithm for segmenting electron microscope images of ceramic bronze-casting moulds

Material characteristics of casting moulds are crucial for understanding the evolution and diversification of bronze ritual vessel production in Bronze Age China. During relevant studies, a Back Scattered Electron (BSE) image detector is commonly employed to analyze mould microstructure, effectively revealing the volume ratios and shape features of the clay matrix, silt/sand particles, and voids. It is always challenging to analyze and cross-compare these BSE images quantitatively since they typically contain numerous phases with highly irregular shapes. Traditionally, time consuming manual point counting or multi-step image processing were used to obtain semi-quantitative results. Addressing these challenges, we have proposed a deep learning method called BCM-SegNet, an optimized Mask R-CNN-based algorithm for segmenting BSE images of bronze casting moulds and cores. Using the proposed method, key parameters, such as area, Feret diameter, roundness, and solidity of segmented particles, can be provided based on well segmented results, even for the images with complex background. Experimental outcomes show that the algorithm achieves a segmentation precision of 95% and an accuracy of around 91%, demonstrating its strong generalization capability. This study provides a significant foundation for micro-feature analysis of archaeological ceramic materials, classification of particles, and determination of technological processes in archaeological research.

Revealing ancient technology: a high-energy X-ray computed tomography examination of a Mesopotamian copper alloy head

Although the origins of lost wax casting extend back into the 5th millennium BCE, it was not until the development of hollow core casting that life-sized metal sculptures could be produced. Based on existing evidence, the earliest adoption of this technique, which involves the inclusion of a clay core within a wax model, occurred in Iraq (Mesopotamia) during the Early Dynastic III period (ca. 2600–2350 BCE). To date, only one hollow core casting from the succeeding Akkadian period (ca. 2350–2150 BCE)—the Sargon Head in the collection of the Iraq Museum—has been studied from a technical point of view. The recent attribution of The Metropolitan Museum of Art's Head of a ruler to this formative period of hollow core lost wax casting provided the impetus for its examination by high-energy X-ray computed tomography—the most practical technique for an object that is continuously on display that could image in 3D the interior morphology of this sculpture given the considerable thickness of its metal walls. This scan revealed a markedly different style of production than the Sargon Head. Although further research on early castings is required to determine the chronological implications of the differences observed and to elucidate more generally the early development of hollow casting technology, the scan of the Head of a ruler provides evidence of some of the challenges encountered and problem-solving strategies used in the casting process.

Thermo-Chemical Characterization of Organic Phase Change Materials (PCMs) Obtained from Lost Wax Casting Industry

The high global energy demand drives the search for sustainable alternatives for energy production and storage. Among the most effective solutions are phase change materials (PCMs). In particular, organic PCMs offer a high capacity to store and release thermal energy in response to external thermal variations, even over a wide temperature range. They find profitable applications in various sectors, from construction to electronics, offering flexibility and considerable energy storage according to need. In the search for new and effective PCMs, reusing by-products from different industries would offer both economic and environmental benefits. With this goal in mind, several organic PCMs with different characteristics and origins were analyzed in the present study. Two of them were by-products of the lost wax casting industry. In fact, we wanted to verify whether this waste could be employed as an effective, low-cost PCM. For comparison purposes, two commercial PCMs were selected, namely a paraffin and a microencapsulated PCM. Finally, a PCM blend was produced by mixing a commercial PCM and a waxy by-product. The five selected or developed PCMs were subjected to different tests to investigate their chemical composition, thermal characteristics, and thermal stability before and after repeated (i.e., 100) cycles of melting and crystallization processes. The results demonstrated that the durability of the non-commercial PCMs with regard to thermal loads was not inferior, and was in some cases even superior, to commercial PCMs. This study therefore proposes an innovative path to reuse the by-products of different production processes to support the environment.

THE LOST WAX TECHNIQUE OF DOKRA ART: AN EMPIRICAL STUDY ON BIKNA VILLAGE OF DISTRICT BANKURA, WEST BENGAL

Among the famous artistic works of Bankura District of West Bengal, Dokra (also known as Dhokra) is an age old traditional non-ferrous metal art of Indian Subcontinent. The term ‘ ‘Dokra’’ generally describes a group of craftsmen, nomadic in nature who spread over the different states i.e. Andhra Pradesh, Chhattisgarh, Orissa, Madhya Pradesh, Jharkhand and West Bengal. Dokra is characterized by its simple and primitive figurines on folk themes, variety of beautifully decorated deities and animal structures. The evidences of Dokra non-ferrous metal crafts trace back to the Harappan Civilization almost 4600 years ago. The dancing girl of Harappan Civilization is an ideal example of Dokra non-ferrous metal casting. This paper is mainly focused on the traditional lost-wax technique (Cire perdue in French) of Dokra metal art of Bikna village of District Bankura still practiced at present. Delighted to say, Dokra art from West Bengal has gained the Geological Indication (GI) Tag in the year of 2018. The present study is qualitative in nature and based on empirical research work on Bikna village involving interviews, oral history and observations. Both primary and secondary data sources were used to accomplish the work.

Reconstructions of the La Tène wagon wheels of Southeast Europe

Summary The examination in the relevant museums of the preserved metal parts of La Tène wagon graves of southeastern Europe enables, firstly, a precise determination of their function, and also the reconstruction of some wheels. The La Tène wheels were usually around 85 cm in diameter, hot iron tyres were pulled over the wooden felloes and fastened with a few additional nails (such as at Balsa or Toarcla). The wooden naves were reinforced with nave rings and pushed onto the axle-arm, the latter having a diameter of circa 5.5 cm. The axle nails prevented it from jumping off the axle-arm. In the case of the middle La Tène wagon wheels found at Curtuiușeni and the late La Tène chariot wheels found at Cugir, buffer rings with a band of circular fittings could be seen on the axle-arm between the axle nail and the nave head. In the case of Cugir the nave rings were made from cast bronze and the buffer ring claddings from wrought bronze.

Innovative Die Component Manufacturing by Using Lost Wax Casting and 3D Printing Processes

Abstract: The project focuses on crafting a casting die for designing the micro jet nozzle of an aircraft engine. The manufacturing of the casting die involves various steps outlined in the procedure. Regular stone material, categorized under ceramic parts, is utilized for constructing the casting die. The primary objective of this project is to integrate additive manufacturing into the production of automobile parts and the construction of mechanical components. We are going to fabricate d casting die by using different material other than regular casting material which is more accurate. This project involves 3Dprinting technology and SLA printing technologies.