Glass Ingots Research Articles

Glassmaking remains from the 12th to 14th centuries CE glass workshop in Boshan, Shandong Province, China

Many glass furnaces producing K2O-CaO-SiO2 glass were excavated in Yanshen Town, Zibo city, Shandong province, dating to the Jin to Ming Dynasties, a large-scale glass-making center recorded in historical sources. According to the typological study of ceramics, the workshop which produced the studied samples dated from the Jin to the Yuan Dynasties (12th to 14th centuries CE), and is one of the earliest archaeological glass workshops found in China. The workshop yielded many semi-finished glass fragments, final products, and glass crucible fragments. We conducted chemical and micro-structural analysis by LA-ICP-AES and SEM-EDS, determining that the glass recipe included feldspar, quartz, nitrate, fluorite, colorants, and probably calcite. These minerals match those in the glass recipes recorded in the historical literature. Glass making comprised at least two steps, namely the pre-melting of raw materials into a semi-finished glass, to which more fluxes were then added to make the final glass products or ingots.

Silver dissolution and precipitation in an Na2O–ZnO–B2O3 metallization paste glass

AbstractThermally stimulated interactions between silver and glass, that is, silver dissolution as Ag+ and precipitation as Ag0 were studied in two glass series of molar target composition xAg2O–(19 − x)Na2O–28ZnO–53B2O3 with x = 0, 0.1, 0.5, 5 and (19Na2O–28ZnO–53B2O3)+yAg2O with y = 0.01, 0.05. These act as model for low‐melting borate glasses being part of metallization pastes. The occurrence of metallic silver precipitates in melt‐quenched glass ingots demonstrated that silver dissolved only in traces (< 0.01 mol%) in the glasses. The dissolved silver was detected by means of Raman spectroscopy and energy‐dispersive X‐ray spectroscopy. Increasing x in the batch could not lead to a significant increase of the silver ion fraction in the glass as possible in binary silver borate glasses. In situ observation of heated AgNO3 mixed with the base glass frit in a hot stage microscope showed that Ag0 precipitation occurs already at the solid state. At higher temperatures, small droplets of liquid silver were found to move freely within the melt, whereas coalescence caused a stepwise increase of their size. These results contribute to the understanding of formation of silver precipitates in metallization pastes described in the literature.

Glass ingots from the Uluburun shipwreck: Addition of glass cullet during manufacture and evidence for the changing context of New Kingdom Egyptian glass production in the late 18th Dynasty

Our recent LA-ICP-MS analyses of glass ingots from the Uluburun shipwreck along with additional samples from Egyptian sites, primarily Amarna, encourage us to question how and where the ingots were produced. Because almost all the approximately 200 glass ingots are either greenish blue, colored by copper, or purplish blue, colored by cobalt, we focus here on these colorants and their attendant trace elements. Based on the evidence for copper and antimony in cobalt-blue glass, we conclude that the most likely explanation is the addition of glass cullet during ingot production, in accordance with suggested evidence from glassmaking texts thought to date to the Late Bronze Age. By comparing the Uluburun ingots with glass from Amarna using multivariate statistics and trace element ratios, we determine that while a few of the ingots might be consistent with Amarna manufacture, the great majority are not, but rather represent production from other workshops, probably following those at Amarna. The importance of these workshops is suggested by our finding that over half of the cobalt-blue Mycenaean relief beads for which trace element data is available were made with Egyptian glass closer to that of the Uluburun ingots than to glass found at Amarna.

Glass ingots from the Uluburun shipwreck: Glass by the batch in the Late Bronze Age

The glass ingots from the Late Bronze Age Uluburun shipwreck (ca. 1300 BCE) provide crucial insight into Late Bronze Age glass production and exchange in the Mediterranean. Almost all of the approximately 200 glass ingots on board the ship were sampled as well as five of the 30 Mycenaean glass relief beads. Here we report the full chemical compositional results for these samples, along with 49 strontium isotope analyses representing at least 48 separate glass ingots. We include as well 355 unpublished analyses of Late Bronze Age Egyptian, Mesopotamian, Levantine, and Aegean glasses; these represent a total of 222 different objects since many of the core-formed vessel fragments are polychrome and each color was analysed separately. The results suggest that the Uluburun glass ingots were produced in as few as 28 discrete production events or batches. The largest batch included at least 16 ingots representing 40 kg of glass with a chemical composition as perfectly uniform as could be determined by our LA-ICP-MS analyses. Cluster analysis and comparison of Ti/Cr and Li/Zr ratios indicate that all of the ingots are Egyptian glass. In addition, based on this new dataset we have identified the first Egyptian glasses to be found at Mesopotamian sites as well as several examples of Mesopotamian glass used to produce Egyptian objects. The Mycenaean glass relief beads on board the ship were also produced with Egyptian glass, although in this case more similar to glass from Amarna than to the Uluburun ingots. These results, coupled with our finding that glass almost identical to ingots found on the ship was used to produce several of the unprovenanced Mycenaean relief beads from museum collections, presents a picture of overall technological continuity combined with geographic flexibility at the end of the Amarna Period in Egypt.

Glass Ingots from the Uluburun Shipwreck: Addition of Glass Cullet During Manufacture and Evidence for the Changing Context of New Kingdom Egyptian Glass Production in the Late 18th Dynasty

Glass Ingots from the Uluburun Shipwreck: Addition of Glass Cullet During Manufacture and Evidence for the Changing Context of New Kingdom Egyptian Glass Production in the Late 18th Dynasty

Glass Ingots from the Uluburun Shipwreck: Addition of Glass Cullet During Manufacture and Evidence for the Changing Context of New Kingdom Egyptian Glass Production in the Late 18th Dynasty

Glass Ingots from the Uluburun Shipwreck: Addition of Glass Cullet During Manufacture and Evidence for the Changing Context of New Kingdom Egyptian Glass Production in the Late 18th Dynasty

Microstructure and mechanical properties of wedge-shaped CuZrAlNd metallic glass ingots

In this study, (Cu43Zr48Al9)100-xNdx (x = 1, 2, 3, or 4 at. %) bulk metallic glasses (BMGs) were successfully prepared by casting in wedge-shaped copper moulds. We studied the effect of rare-earth neodymium (Nd) addition on the glass forming ability (GFA) and mechanical properties of (Cu43Zr48Al9)100-xNdx. The enhancement of GFA in Cu–Zr–Al BMGs with Nd addition could be well explained by the atomic size difference δ, electronegativity difference Δx and negative mixing enthalpy ΔHmix. Of the alloys investigated, the (Cu43Zr48Al9)97Nd3 BMG exhibited the best GFA, with a high compressive strength of 2045 MPa. To prepare the wedge-shaped cast, the melt was subjected to a wide range of cooling rates that allow investigation of the transformed microstructure and dynamics. A U-shaped crystal-to-glass phase transition boundary was obtained. Based on the microstructural analysis of (Cu43Zr48Al9)97Nd3, we found that the equilibrium microstructure of this alloy consists of [CuZr + Cu10Zr7 + CuZr2].

Glass-working evidence at Dibba, United Arab Emirates: An archaeometric study

Glass ingots found in an archaeological site discovered at the town of Dibba, United Arab Emirates, were analyzed using X-ray Fluorescence Spectroscopy in order to establish their elemental composition, and their association to glassware fragments found in the same site.Quantitative XRF analysis of the samples revealed that the glass under investigation is based on plant ash soda-lime glass, with soda predominant over potash, lime, and magnesia indicating the use of a plant ash source for the alkali. The results also showed that all the samples have similar elemental composition, with little variations in concentrations.Our findings prove that the glassware and ingots found in the site have the same elemental compositions. The sheer volume of glass ingots discovered in the site, coupled with the presence of glassware fragments, indicate the existence of a glass workshop in Dibba archaeological site during the period between the late first century BCE and the end of the first century AD.

Implementation of fluorophoshate laser glass for short length active fiber at 1.5 μm

We successfully fabricated a short-length active fiber based on fluorophosphate (FP) laser glass by the rod-in-tube technique and fiber drawing process. The base FP laser glass composition, 20Al(PO3)3-40BaF2-40SrF2 was used for making glass fiber with appropriate core and clad profiles. The physical, thermal, optical, and spectroscopic properties of core and clad materials were optimized in order to implement FP laser glass for active glass fiber fabrication. The difference of refractive index and the glass transition temperature between core and clad glass ingots was obtained to be close to 0.004 and 6 °C, respectively. The spectroscopic properties of FP laser glasses were also derived. The gain and gain coefficient of the indigenously fabricated glass fiber were measured to be 10.29 dB and 0.60 dB/cm at 1550 nm from a 17 cm bare fiber, respectively. The results direct that the short length active fiber based on FP laser glass could be useful for compact all-optical fiber amplifier at 1.5 μm.

Glass ingots, raw glass chunks, glass wastes and vessels from fifth century AD Palatine Hill (Rome, Italy)

The research focused on a collection of 20 glass fragments, including raw glass chunks and ingots, wastes and vessels found at the Palatine Hill in Rome and dated to the first half of the fifth century AD. The analyses performed by scanning electron microscopy (SEM)-energy-dispersive spectrometry (EDS), electron microprobe (EMPA), inductively coupled plasma mass spectrometry (ICP-MS), laser ablation-ICP-MS (LA-ICP-MS) and X-ray diffraction (XRD) showed that all samples are constituted by natron-based soda–lime–silica glass. De/colouring agents were lead stannates (yellow brownish), copper and lead antimonates (green), different Fe2+/Fe3+ ratios (green, light green and yellow-green), Fe2+ (prevailing over Fe3+; aqua blue), cobalt (blue), metallic copper (reddish) and manganese (colourless). As for provenance, two samples were of Levantine provenance, nine samples were likely of Egyptian origin (HIMT glass) and, similarly, seven samples (or maybe nine, adding ingots nos. 1–2) were likely of North African provenance (HIMT/RNCBGY 1 glass).

An Early Historic Assemblage Offshore of Godawaya, Sri Lanka: Evidence for Early Regional Seafaring in South Asia

Investigations in 2010 by an international team of maritime archaeologists yielded a concentration of artefacts identified here by the authors as the remains of a shipwreck off the southern coastal village of Godawaya, Sri Lanka. The major findings from this site include many quern stones, various types of ceramics, and glass ingots. The comparative study of the artefacts from the Godawaya site and terrestrial sites of Sri Lanka and India suggest that the ship might have originated from the southern part of the Indian subcontinent. Based on analysis of the artefacts and radiocarbon dating of wood fragments from the site, a broad date of 2nd BCE to 2nd centuries CE is assigned to the assemblage, placing it within the early historical period. Thus, this is the earliest known and as-yet investigated shipwreck in South Asia. The survey findings are discussed and the assemblage is contextualised within the present lack of evidence for early vessels and seafaring in the region.

Red glass for the Pharaoh

Glass in ancient Egypt appears to have been used as a substitute for precious stones that were not available in the country. Here the process of glass manufacture is traced through the examination of the fragmentary remains of ceramic reaction vessels and crucibles used in the production of small glass ingots.

Fabrication of highly homogeneous As2Se3 glass under argon flow

The present study relates to a new method for the synthesis of As2Se3 glass in a controlled atmosphere. The advantage of this technique is that it does not require sealing of the silica reaction container and therefore makes it likely to substitute the current industrial batch by batch synthesis which actually needs very expensive single-use sealed silica vessels.An experimental device has been developed for these purposes. It is equipped with a stirring mechanism to homogenize the molten bath. In order to avoid contamination by oxygen and moisture, the synthesis is carried out under argon flow (pressure of 1bar). Material losses during synthesis can be reduced to less than 2% when temperature is progressively increased up to 430°C. Bulk glass ingots are finally obtained according to a two-step annealing process. Their chemical composition is analyzed by EDS and shows a variation range of less than 0.2%. The excellent reproducibility of the given method is also confirmed by the refractive indexes, that do not differ for more than 1·10−3 from one another.Adverse absorption bands due to oxygen do not occur in the 8–12μm spectral region when 1000ppm of Mg is added. As no distilling operation has been carried out until now, the magnesium oxide partially keeps staying in the glass and leads to scattering losses at short wavelengths.

Shear stability of metallic glasses

The effect of sample size on the shear deformation and compressive plasticity of different metallic glasses were investigated. The experimental results showed that the deformation and fracture behaviors of samples prepared from chemically identical Zr-, Ti-, Fe-, or Mg-based metallic glass ingots were strongly dependent on the sample size and machine stiffness, and a super-high compressive plasticity was achieved in the Zr-based metallic glasses with sample size of 1.0 mm in width. It is also found that the sample size can significantly influence the density of elastic energy dissipated in the shear band: with sample size decreasing and machine stiffness increasing, the density of the elastic energy dissipated in the shear band of metallic glasses is prominently decreased, thus the shear deformation turns to be more stable, resulting in the improvement of plasticity in ductile metallic glasses and the transition from fragmentation fracture to shear fracture in brittle metallic glasses. This finding is important for the potential applications of the present metallic glasses and for designing new metallic glasses with better mechanical properties.

The provenance of some glass ingots from the Uluburun shipwreck

The discovery of a Late Bronze Age trading vessel at Uluburun near Kaş off the Turkish coast offers exciting possibilities for our understanding of Bronze Age trade. On board the ship was a large consignment of glass ingots that were assumed to originate either from Mesopotamia or Egypt. This paper presents the results of major and trace elemental analyses of three deep blue and turquoise glass ingots from the Uluburun wreck, and for the first time securely demonstrates that their composition is consistent with an Egyptian origin. The compositional similarity of the glass ingots to glasses from the Mycenaean world suggests that Egypt was exporting to that region via trading ships such as that from Uluburun.

PIXE–PIGE analysis of Carolingian period glass from Slovenia

Glass artifacts excavated from the Late Roman and Carolingian period site at Bašelj Slovenia were analyzed by the combined PIXE–PIGE method using a proton beam in air. The results show that the majority of objects and glass ingots were made of traditional Roman, natron-type glass. Increased titanium and other impurities were found indicating that the glass had been recycled several times. As the composition of the ingots was similar to the other objects, a possibility exists of a secondary glass workshop in the local vicinity. The typologically and stratigraphically dated objects confirm that the Roman glassmaking continued in the area of Eastern Alps well into the 9th century.

The Conservation of Glass Ingots from the Bronze Age Uluburun Shipwreck

Various desalination, drying, consolidation and reconstruction strategies have been employed in the conservation of an unparalleled collection of Bronze Age glass ingots found on the Uluburun shipwreck, excavated by the Institute of Nautical Archaeology (INA) between 1984 and 1994. Presented here are the results of a survey undertaken to determine the effects of these different treatments. Included is an in-depth description of the treatment of four ingots, as well as the use of different gap-filling materials: Paraloid ® B-44, Multiwax W-445, a cellulose powder/Paraloid ® B-72/fumed silica mixture and a two-part epoxy putty. A general treatment approach for ancient glass excavated from a marine environment is suggested based on the conservators' experiences, the findings of the survey report and the re-examination of treated ingots.

Evaluation method of TiO/sub 2/-SiO/sub 2/ ultra-low-expansion glasses with periodic striae using the LFB ultrasonic material characterization system

Experimental procedures and standard specimens for characterizing and evaluating TiO2-SiO2 ultra-low expansion glasses with periodic striae using the line-focus-beam (LFB) ultrasonic material characterization system are discussed. Two types of specimens were prepared, with specimen surfaces parallel and perpendicular to the striae plane using two different grades of glass ingots. The inhomogeneities of each of the specimens were evaluated at 225 MHz. It was clarified that parallel specimens are useful for accurately measuring velocity variations of leaky surface acoustic waves (LSAWs) excited on a water-loaded specimen surface associated with the striae. Perpendicular specimens are useful for obtaining periodicities in the striae for LSAW propagation perpendicular to the striae plane on a surface and for precisely measuring averaged velocities for LSAW propagation parallel to the striae plane. The standard velocity of Rayleigh-type LSAWs traveling parallel to the striae plane for the perpendicular specimens was numerically calculated using the measured velocities of longitudinal and shear waves and density. Consequently, a reliable standard specimen with an LSAW velocity of 3308.18 +/- 0.35 m/s at 23 degrees C and its temperature coefficient of 0.39 (m/s)/degrees C was obtained for a TiO2-SiO2 glass with a TiO2 concentration of 7.09 wt%. A basis for the striae analysis using this ultrasonic method was established.

Effect of crystallization heat treatment on the microstructure and biaxial strength of fluorrichterite glass‐ceramics

The purpose of this study was to evaluate the effect of crystallization heat treatment on the flexural strength of potassium fluorrichterite glass-ceramics for biomedical applications. After melting and casting, discs were sectioned from the glass ingots, randomly divided into 10 groups, and heat treated at various temperatures ranging between 890 degrees C and 925 degrees C for various durations. One group was air-abraded after heat treatment. XRD revealed the presence of fluorrichterite and fluormica for all heat-treated groups. SEM confirmed the presence of both fluorrichterite and fluormica crystals. Crystal size increased with temperature and duration of the heat treatment. The mean flexural strength after air abrasion was not significantly different than that of the other groups except the group heat treated at 925 degrees C. The mean flexural strength was maximum after heat treatment at 900 degrees C for 1 h (497.6 +/- 25.5 MPa) and decreased linearly with the longer durations of heat treatment at 900 degrees C.

Metallic glass ingots based on yttrium

We report a family of yttrium metallic alloys that are able to form glassy ingots directly from the liquid, as well as forming bulk-sized amorphous rods with diameters over 2 cm by water cooling of the alloy melt sealed in quartz tubes. It is apparent that, in addition to the strong chemical interaction among the components, the simultaneous occurrence of well-distributed atom sizes and a strongly depressed liquidus temperature in multicomponent metallic alloys is responsible for the formation of glassy ingots.