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Conventional high-chromium ferritic / martensitic steels, such as T91 and AISI 316 L as well as the new oxide dispersed strengthened (ODS) steels, i.e. Fe-Cr (ferritic or martensitic) with a fine Y2O3 dispersion, are promising candidates as structural materials for applications in aggressive environments. In order to improve the efficiency and lifetime of structural materials for liquid metal fast reactor (LMFR), where liquid lead (Pb) is used as coolant, the investigations are currently focused on the interfacial phenomena occurring at the liquid Pb/steel interfaces. The better understanding of the interfacial phenomena is the key issue for the selection of structural materials meeting the requirements of the demanding application. In the present work, a fundamental study on the wetting characteristics and the interfacial phenomena of liquid Pb in contact with T91, AISI 316L, ODS- 12Cr and ODS-14Cr steels over the temperature range 550�820�C and under different oxygen containing atmospheres is reported.

The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5-11 December, to 17.5% (25/143 samples) in the week 12-18, to 65.9% (89/135 samples) in the week 19-25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool.

Proper investment in mushroom production (farming and wild mushroom picking activities) may represent a winning strategy for many countries, including Italy, to better face the problems of food security and environmental impact, and to break away from imports, enhancing the local products. However, the risk related to the consumption of poisoning species requires governments to implement or reinforce effective control measures to protect consumers. Mushroom identification by phenotype observation is hardly applicable if morphologically-similar species, non-whole specimens, or clinical samples are involved. Genotypic analysis is a valid alternative. An ongoing research project involving the Experimental Zooprophylactic Institute of Lazio and Tuscany, the regional Mycological Inspectorate, the Tuscany Mycological Groups Association, and the Department of Veterinary Sciences of the University of Pisa aims to reinforce the collaboration among institutions for the management of mushroom poisoning. The core’s project aims to develop an internal genetic database to support the identification of wild and cultivated mushroom species in the Italian territory. The database will include Internal Transcribed Spacer (ITS) sequences retrieved from official databases (the NCBI GenBank and the BOLD system) which are considered to be reliable, after a proper selection process, and sequences from specimens collected directly and identified by expert mycologists. Once it is validated, the database will be available and further implementable by the official network of national laboratories.

Gilthead seabream and European seabass are among the most appreciated farmed fish species in the European Union. This case study analysed the self-control plan procedures adopted in an offshore cage farm in Central Italy to prevent anisakids infection, in the light of the Anisakis contamination pathways previously proposed for farmed Atlantic salmon (Salmo salar), and of the criteria recommended by the European Food Safety Authority. Moreover, the results of the visual parasitological examination conducted by the Food Business Operator, as part of the self-control plan, on 5% of the total specimens with commercial size (2016–2020 period) were also considered. Results show an extremely low to negligible risk for the introduction of ascaridoid larvae, confirming the absence of these parasites in farmed specimens of both species. However, few implementations to the self-control plan are suggested for obtaining the derogation to preventive freezing, as established by the European legislation. These include the parasitological examination of a statistically significant sample of the farmed specimens (commercial sizes) conducted by trained personnel, as well as of farmed specimens found dead or underdeveloped (runts) and of wild specimens of other species which may enter the cages. The proposed approach can be adapted by other farms by adjusting the sample size based on the production volume and risk categorization. The exemption from the preventive freezing would represent an additional market opportunity for Italian aquaculture plants.

The present study aims to deepen the knowledge on the corrosion behavior of martensitic T91 steel in contact with liquid lead in view of its application in advanced nuclear energy systems. Steel samples have been analyzed after the immersion in stagnant molten lead at different temperatures (550°C to 650°C) and for an exposure time of 550 h. In order to evaluate the influence of different oxidizing conditions, the corrosion tests were performed under both Ar and Ar-H2 mixtures. Within the temperature range applied, the oxygen content in the liquid lead was Co = 6.8±2.7 × 10−2 wt% and Co = 9.2±3.6 × 10−8 wt%, respectively. When the Ar atmosphere was applied, dissolution of iron and chromium has been observed for temperature above 590°C. Conversely, under an Ar-H2 mixture atmosphere, mainly the presence of internal oxidation along the grain boundaries whose depth increases with temperature was detected.

Several pufferfish species belonging to the Tetraodontidae family are currently present in the Mediterranean Sea. Since 2013 Lagocephalus sceleratus is increasingly reported also along Italian coasts, where other two species of less concern, Lagocephalus lagocephalus and Sphoeroides pachygaster, have also occured since a long time. This study represents one of the first attempts to sistematically describe the occurrence in the Mediterranean, and in particular along Italian coasts, of the three aforesaid species, in order to characterize an emerging public health hazard. Reports were searched in scientific articles and dedicated online databases. The following data were collected: number of specimens and type of record, geographical location and date of report, fish size, depth and type of seabed. Overall, at least 111079 individuals of the three species were found in the Mediterranean Sea, including 110237 specimens of L. sceleratus (since 2003), 126 of L. lagocephalus (1878–2017) and 716 of S. pachygaster (1979–2017). The evident differences confirm the invasive character of the toxic Lessepsian immigrant L. sceleratus, the species of main public health concern. Despite this species was recorded along Italian coasts in low numbers (0.08% of the total individuals of L. sceleratus) and its current distribution is limited to southern regions, the picture could change rapidly. Moreover, the collected data show that most L. sceleratus specimens have a large size and are mainly caught by commercial fishing gears. These factors may increase the risk of this species entering the seafood chain with serious consequences for consumers’ health. Results suggest that the presence of L. sceleratus should be strictly monitored. Institutional measures should be implemented to inform people as regards a new hazard that has the potential to affect the Italian seafood chain.

In this work, we have analyzed the key features of Rickettsia spp. maintenance in Dermacentor marginatus ticks in four regions of the northern Mediterranean area, where extensive investigations are currently lacking. For this purpose, 380 adult D. marginatus ticks were collected from vegetation and wild ungulates during a 3-year study. A host-vector-pathogen interaction approach was applied to investigate the key components of the disease systems and evaluate their respective weight in the intensity of infection in natural foci. A high variability in the R. slovaca infection rate among sampling sites was observed, whereas R. raoultii was sporadically present and at low infection rates. Dermacentor marginatus presence was confirmed in all the investigated regions. The local wild boar population showed a strong association with adult D. marginatus ticks. The results of this investigation suggest that wild boars not only maintain D. marginatus populations by feeding adult ticks, but may also have a potential role in the eco-epidemiology of rickettsioses, as carriers of rickettsiae-infected ticks. The public health implications of these results are discussed.

The surface tension of liquid Ag Cu eutectic alloy has been measured in a wide range of oxygen partial pressures using two different methods: the constrained drop method and the electromagnetic levitation method. In order to investigate the influence of oxygen potential on the surface tension of the Ag 40Cu (at.%) eutectic alloy, the oxygen partial pressure was varied between 8.62 × 10−15 and 2.42 Pa. At low oxygen partial pressure, the surface tension of the Ag Cu eutectic alloy measured in the temperature range of 1223–1476 K, shows temperature dependence in a good agreement with previously reported results. At higher oxygen partial pressures, the decrease in surface tension is more pronounced and the oxygen adsorption on the surface accordingly increases. Moreover, at high oxygen partial pressure, the oxygen adsorption on the Ag Cu eutectic alloy was found to be far greater than the expected saturation limit taking into account the theoretically calculated surface concentration of Cu in the Ag Cu eutectic alloy and the surface excess of oxygen on the molten Cu at saturation. This phenomenon can be explained with a model where the surface of the Ag Cu eutectic alloy undergoes Cu-substitution at the Ag sites during the oxygen adsorption process.

Gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax) are among the most popular fish on the Italian and European market. The present study aimed to assess the occurrence and localization of ascaridoid nematodes in wild specimens of these two species caught in a previously not investigated area of the Tyrrhenian Sea (FAO subarea 37.1.3). Forty gilthead seabream and forty-seven European seabass were analysed through visual inspection and chloro-peptic digestion. All the parasites collected were submitted to morphological and molecular analysis, targeting a fragment of the cytochrome oxidase subunit 2 (cox2) and of the internal transcribed spacer (ITS) genes. No Anisakis spp. were found. As regards other ascaridoid nematodes, seven larvae of Contracaecum rudolphii A (2 in the belly flaps and the rest in the viscera) (Prevalence - P: 2.5 95% Confidence Interval - CI: 0–7.3%; Mean Abundance - MA: 0.017; Mean Intensity - MI: 7) and one visceral larva of Hysterothylacium sp. (P: 2.5 95% CI: 0–7.3%; MA: 0.025; MI: 1) were found in two different specimens of S. aurata. Seventeen larvae of C. rudolphii A were found in the viscera of six D. labrax (P: 12.7% 95% CI: 3.3–22.3%; MA: 0.15; MI: 1.17). The absence of Anisakis sp. in S. aurata agrees with literature data, while variable prevalence values had been previously reported for D. labrax, generally higher in Atlantic grounds. The occurrence of C. rudolphii A and Hysterothylacium spp., nematodes of less (however unknown) or negligible zoonotic impact, respectively, contributes to the characterization of ascaridoid epidemiology in these commercially relevant species. In addition, the presence of the species C. rudolphii A in S. aurata is reported for the first time. The present results contribute towards the parasitological risk assessment of this Italian maritime area, which is also highly dedicated to the aquaculture of S. aurata and D. labrax.

The present study is an overview of the surface properties of liquid Al-Ni alloys, which are of great importance for the design and development of new Al-Ni and Ni-based industrial alloys, widely used as functional and structural materials. The solidification and thus, the microstructural evolution are directly dependent on the interface/surface properties of metallic melts. Therefore, numerical simulation of microstructure evolution requires reliable property data as input to such models. Taking into account the experimental difficulties related to a high reactivity of liquid Al-Ni alloys and the effects of impurities on their surface properties, the surface tension over the whole concentration range has been determined in the frameworks of three international research projects. Namely, the surface tension measurements have been carried out by both traditional container-based and as an alternative, containerless methods within the ESA-MAP ThermoProp and ESA-MAP Thermolab Projects and also under the EU FP6-IMPRESS Project. The obtained datasets were analysed and subsequently compared with the model predicted values as well as with the literature data. A strong exothermic mixing characterises the Al-Ni system and the presence of a few intermetallic compounds in the solid state leads to the formation of short range ordered elements or complexes in the liquid phase, at least near the melting temperature, which significantly affects the surface properties of alloy melts. Aiming to estimate the effects of short range ordering on these properties, the Compound Formation Model (CFM) and the Quasi Chemical Approximation (QCA) for regular solution were applied.

The knowledge of thermophysical properties of liquid Co-Si alloys is a key requirement for manufacturing of composite materials by infiltration method. Despite this need, the experimental and predicted property data of the Co-Si system are scarce and often inconsistent between the various sources. In the present work the mixing behaviour of Co-Si melts has been analysed through the study of the concentration dependence of various thermodynamic, surface (surface tension and surface composition) and structural properties (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the framework of the Compound Formation Model (CFM) and Quasi Chemical Approximation for regular solutions (QCA). In addition, the surface tension of the Co22·5Si77.5 (in at%) eutectic alloy, that is proposed to be used as the infiltrant, has been measured by the pendant drop method at temperatures ranging from 1593 to 1773 K. The results obtained were discussed with respect to both, temperature and concentration, and subsequently compared with the model predictions and literature data.

Eustrongylides spp. are cosmopolitan parasitic nematodes with several freshwater fish species as intermediate or paratenic hosts, rarely reported as zoonotic agents. This work aims to report, for the first time, the occurrence of this parasite in specimens of big scale sand smelt (Atherina boyeri) caught in the lake Massaciuccoli (Northwest Tuscany, Italy). Totally 3317 specimens of A. boyeri were collected in three different samplings (August–October 2019). Fish were visually examined and then submitted to artificial digestion. Visible parasites were collected and counted after both procedures, then they were identified to genus level by microscopic examination and to species level by molecular analysis of the ITS gene region. Overall, 75 nematodes identified as larval stages of Eustrongylides excisus were found (P: 2.3% 95% CI 1.8–2.8; MA: 0.02; MI: 1), in the viscera and in the muscle. A. boyeri is a highly appreciated fish species in several Italian areas as well as in various Mediterranean countries. Beside an epidemiological interest due to its role in the parasite cycle, the report of E. excisus in the study area arises possible quality and public health issues. Therefore, also considering the method of preparation of A. boyeri and that lately the increasing consumption of raw fish has also targeted freshwater fish species, it is essential to communicate the presence of this hazard and the need of applying appropriate sanitary measures to all FBOs along the supply chain and to consumers.

Among additive manufacturing (AM) processes, Selective Laser Melting (SLM) is the most diffused layer by layer method for manufacturing 3D components. It is based on local melting, induced by a laser scanning, on a powder bed; the limited dimensions of the liquid pool provoke rapid cooling rates which can be associated to significantly finer microstructure than the one obtained by a conventional casting process. Moreover, being the remelting of pre-existing pools, it is of relevant interest to investigate the wettability and the reactivity at high temperature of alloys produced by SLM. In the panorama of alloys for AM, the AlSiMg system is one of the most used, as it belongs to wide family of the Al–Si alloys, extensively used for conventional casting and die-casting technologies, and it offers good weldability. Therefore, the present work has the goal of investigating the high temperature behavior of the SLMed AlSiMg parts. Wettability tests on Al2O3 plates were performed considering two different atmospheres (vacuum and Argon) and the contact angle results compared; surface morphology together with the microstructures and the chemical composition variations were analyzed.

The titanium alloy Ti–6Al–4V (Ti64) is a very widely applied alloy with extreme importance in the fields of aerospace, automotive, and biomedicine. For a large range of manufacturing methods that involve the liquid phase, such as casting, metal injection molding, thermal spraying, and additive manufacturing, process simulations are an important tool for the optimization and development of the fabrication process. Reliable thermophysical property data of Ti64 in the solid and the liquid phase are necessary inputs to such models. Due to the high melt reactivity of titanium alloys with container materials, measurements performed using conventional thermophysical equipment are usually impossible. Precise benchmark measurement of thermophysical properties (surface tension, viscosity, specific heat, total hemispherical emissivity, thermal conductivity, electrical resistivity, mass density) of Ti64 is presented in the undercooled liquid phase using containerless electromagnetic levitation on board the International Space Station (ISS). The obtained values are compared with predictive models that can help to analyze the data for other compositions of the alloy system. The property values are applied to simulations of industrial fabrication processes, to optimize these processes and thus the product quality., publishedVersion

The present work is aimed to highlight the interfacial properties (surface tension and wettability) of metallic systems involved in the additive manufacturing processing (AM) and their importance for design and development of new candidate materials as it has been already done in the field of joining processes (soldering, brazing, welding). The surface properties of Al-12.6Si (in wt pct) alloy, taken as a reference alloy of a class of additive manufacturing Al-Si based alloys, were investigated. The contact angles of pure Al and of Al-12.6Si alloy in contact with Al2O3 substrates were obtained by applying the sessile drop method under different working atmospheres. The new reference data on the wetting properties of the Al-12.6Si/Al2O3 system can be useful for design and development of new Al-Si-based alloys to be used in AM. The surface tension and the surface segregation of liquid Al-Si alloys were calculated as functions of composition by using Butler’s model and the results obtained were compared to available literature data.

In order to investigate a protective coating approach for nuclear applications, two different aluminum rich layers were deposited on T91 steel coupons: Ti-Al-N films were grown via High Power Impulse Magnetron Sputtering and Al O coatings were produced by Radio Frequency Magnetron Sputtering. In this exploratory work, coated specimens were corrosion tested in stagnant Pb at 550 °C for 1200 h and both types of coatings proved to be effective in protecting the substrate from the harsh environment. Due to the severe experimental conditions, the Al oxide film underwent some mechanical changes, while, the nitride coating demonstrated its noteworthy stability.

Pufferfish may be responsible for human intoxications due to the accumulation of a potentially lethal neurotoxin, called tetrodotoxin (TTX). While traditionally some species of pufferfish are consumed in Japan, their marketing is banned in the EU. However, their illegal presence in mislabelled products has been reported. Moreover, some species of the genus Lagocephalus spread in the Mediterranean Sea during the last decades due to the Lessepsian migration phenomenon and they may represent a significant emerging risk within the European seafood chain. This study aimed at finding a suitable molecular marker for quickly identifying Lagocephalus species in fresh and processed products. All available sequences of COI and cytb mitochondrial genes were used to create different length datasets (long and short fragments) to be used to produce NJ trees depicting genetic relationships for Lagocephalus spp. On the basis of its higher variability, cytb gene was selected as the molecular target and 17 new complete sequences of 6 Lagocephalus species, deriving from reference samples, were produced and included in the datasets. Then, a primer pair for amplifying a 130bp cytb polymorphic fragment from all of the Lagocephalus spp. was designed for identifying sixteen mislabelled commercial products containing pufferfish with degraded DNA. Cytb dataset's phylogenetic analysis supported the most recent species classification of the Lagocephalus genus and highlighted the presence of toxic L. spadiceus in the products. The analysis of the proposed short fragment could represent a reliable tool to protect European consumers from the emerging risk associated to toxic Lagocephalus spp.

The corrosion behaviour of oxide dispersion strengthened (ODS) steels with different chromium contents (9, 12 and 14 wt% Cr) is investigated in stagnant liquid lead at a temperature of 973 K for 2000 h. Under an oxygen concentration close to the passivation domain (i.e. Co ~10-5-10-4 wt% O), neither an internal oxidation zone in the steel matrix, nor dissolution attack caused by liquid lead or its penetration is observed. Indeed, thin layers of chromium rich oxides with different compositions are detected.

Lead alloys are attractive candidates as coolants for future generation nuclear reactors (fast reactors). Unfortunately, they easily corrode structural steels of reactors. To mitigate this phenomenon, surface protective coatings may be applied. In this study, T91 steel (Cr9Mo1) samples were coated with aluminum oxide coatings (Al-O) deposited by radio frequency magnetron sputtering. The alumina coatings were characterized using scanning electron microscopy–energy dispersive spectroscopy, x-ray diffraction, and tribological techniques. A corrosion test of coated steel samples was performed in stagnant lead at 550 °C for 1200 h and none of the samples revealed corrosion signs.

Integration of graphene into electronic circuits through its joining with conventional metal electrodes (i.e., gold) appears to be one of the main technological challenges nowadays. To gain insight into this junction, we have studied the physicochemical interactions between SiC-supported graphene and a drop of molten gold. Using appropriate high-temperature experimental conditions, we perform wetting experiments and determine contact angles for gold drops supported on graphene epitaxially grown on 4H-SiC. The properties of the metal/graphene interface are analyzed using a wide variety of characterization techniques, along with computational simulations based on density functional theory. In contrast with the established literature, our outcomes clearly show that graphene is translucent in the gold/graphene/SiC interface, and therefore its integration into electronic circuits primarily depends on the right choice of the support to produce favorable wetting interactions with liquid gold. The work performed at the University of Alicante was funded by the Spanish “Ministerio de Economía y Competitividad” (Grants MAT2016-77742-C2-2-P and MAT2017-86992-R) and the “Generalitat Valenciana” (PROMETEO II/2014/004-FEDER). The work performed at the University of Sevilla was funded by the Spanish “Ministerio de Economía y Competitividad” (Grant CTQ2015-64669-P), “Junta de Andalucía” and European FEDER (Grant P12-FQM-1595). Also, M.M. thanks the E2TP CYTEMA-Santander Program for their financial support. The work performed at the Foundry Research Institute was funded by the Ministry of Science and Higher Education of Poland (Project No. IOd-6619/00).

Tattoo skin disease (TSD) is a poxviral disease typical of cetaceans. Two juvenile and well-preserved male striped dolphins (Stenella coeruleoalba), found stranded along the Tuscany and Latium coasts of Italy in 2015 and 2016, respectively, showed typical skin lesions ascribable to TSD. Histological, ultrastructural and biomolecular investigations confirmed a poxviral aetiology for the aforementioned skin lesions. To our knowledge, this should be the first report of TSD in cetaceans stranded along the Italian coastline. As organochlorines like PCBs and DDTs are known to be highly immunotoxic, the tissue loads of these contaminants were evaluated, in order to increase our knowledge on their potential role as well as on the relationships between the level of exposure to these pollutants and poxviral infection's occurrence.

Oxide dispersion-strengthened (ODS) steels are being studied as potential materials for future Generation IV concepts of Nuclear Fast Reactors. In particular, the use of heavy liquid metals (HLM), lead and lead bismuth eutectic alloy, is foreseen as coolant and target. However, most of the structural materials used traditionally, suffer severe damage when in contact with HLMs. Structural materials such as the austenitic 316L and the ferritic–martensitic T91 steels have been considered for operation at temperature lower than 823 K. On the other hand, for operations at elevated temperature and under severe neutron exposure environment, the ODS steels are taken into account and currently studied. In the frame of the FP7-GETMAT (Generation IV and Transmutation Materials) project, ODS steels containing 12 wt% Cr were tested in different conditions and environments, comparing experimental techniques and results. This paper reports the results of the study on the behaviour of the 12Cr-ODS steel in contact with molten lead at the temperature of 923 K. The corrosion tests were performed both in a static cell (CorAL) and in flowing conditions, in a natural convection loop (COLONRI II), in Pb, for an exposure time up to 2000 h. The microstructure analysis of the specimens was done before and after the corrosion tests. The results of the corrosion experiments in both experimental facilities are described and the characteristics of the oxides developed on the 12Cr-ODS steel are discussed.

New dietary habits have favored an ever growing popularity of Eastern country cooking style and in particular of sushi. Even though the Reg. (EU) 1379/2013 does not apply to restaurants and caterers, the Reg. (EU) 1169/2011 establishes that all the information they provided to the final consumer have to meet the transparency requirements as regards the description of the ingredients used for the preparation of food. The present study aimed at performing a molecular based survey to identify the seafood species used in the sushi preparations at the retail level. A total of 185 samples were collected from sushi venues and supermarkets and DNA barcoding, followed by a pairwise divergence and Neighbor Joining clustering analysis, was applied in order to verify the information declared at purchase. Rather than to a proper training of Food Business Operators working at the catering level, the low mislabeling rate found in this study (3.4%) could be ascribed to the standardization of the products sold in ethnic restaurants. In fact, the common practice of proposing standardized menus always relying on the same species of fish could limit the risk of mislabeling occurrence.

The systems containing highly reactive element such as Ti are the most difficult to be determined experimentally and therefore, it is often necessary to estimate the missing values by theoretical models. The thermodynamic data of the Al–Ti system are scarce, its phase diagram is still incomplete and there are very few data on the thermophysical properties of Al–Ti melts. The study on surface, dynamic and static structural properties of liquid Al–Ti alloys has been carried out within the framework of the Compound Formation Model. In spite of the experimental difficulties, the surface tension of liquid Al–2 at.%Ti alloy has been measured over a temperature range by the pinned drop method.

Results of a thermophysical characterization of a Fe-Cr-Mo alloy in the solid and liquid phases are reported. Methods applied include calorimetry, dilatometry; the laser flash technique for thermal diffusivity measurement and ultrasound pulse echo for the measurement of the room temperature sound velocities and elastic constants. Density in the liquid phase and surface tension were measured by optical dilatometry and by the oscillating drop method on electromagnetic levitated specimen. In addition, surface tension and viscosity were measured by the oscillating drop method on board parabolic flights under reduced gravity conditions. The methods applied and results obtained are presented. This work represents a collaborative effort, including round robin measurements in different laboratories for a characterization of the basic thermophysical properties needed for process simulation.

The mass transfer phenomena between a liquid metal and the surrounding gas phase play an important role in several technological processes: the existence of oxygen fluxes can strongly affect the properties of the gas–liquid interface. Here, known kinetic criteria will be connected to saturation laws and arranged in a series of tests easily applicable to real cases in order to forecast the steady configuration of the phases. The case of tin will be discussed.

Based on the phase diagram evidence of the existence of three intermetallic compounds, the phenomenon of compound formation in Ni–Ti liquid alloys has been analysed through the study of surface properties (surface tension and surface composition), dynamic properties (chemical diffusion) and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short range order parameter) in the frame of compound formation model (CFM).

In previous works a theoretical analysis was developed for the interactions of a pure liquid metal and an oxidizing atmosphere in both an inert gas carrier and a vacuum. In particular, the effects of oxidation reactions taking place in the gas phase and the evaporation of the condensed oxides were considered. In both cases the presence of oxidation phenomena contributed to maintaining interface cleanness and then strongly affected the shape of the boundary separating the oxidation and de-oxidation regimes. In this work we present a more general physico-mathematical analysis, which is extended to liquid binary alloys and their oxides. The theoretical results obtained indicate that the behaviour of the alloy towards oxygen tends to be similar to that of the less oxidizable component: so the existence of a volatile oxide can often prevent surface oxidation even if the corresponding metal is present in low percentages.

This project is motivated by the need to systematically study the influence of oxygen on liquid metallic alloys and their thermophysical properties such as surface tension, viscosity, and density. Information obtained would serve as a benchmark for the quality of ground based experiments. It would also lead to the development of improved physico-chemical models providing a deeper understanding of the basic interaction mechanisms. A Metal(Alloy)-Oxygen system has been described using different models. The theoretical results obtained are substantiated by own experimental data as wwell as those reported in the literature.

The surface tension, density, and viscosity of the Ni-based superalloy CMSX-4® have been determined in the temperature ranges of 1,650–1,850 K, 1,650–1,950 K, and 1,623–1,800 K, respectively. Each property has been measured in parallel by different techniques at different participating laboratories, and the results are compared with the aim to improve the reliability of data and to identify recommended values. The following relationships have been proposed: density-ρ (T) [kg· m−3] = 7,876 − 1.23(T − 1,654 K); surface tension-γ (T) [mN·m−1] = 1,773 − 0.56 (T − 1, 654 K); viscosity-η (T) [mPa·s] = 8.36 − 1.82 × 10−2(T − 1,654 K). For a comparison, surface-tension measurements on the Al-88.6 at% Ni liquid alloy with the same Al-content as the CMSX-4® alloy were also performed. In addition, the surface tension and density have been theoretically evaluated by different models, and subsequently compared with new experimental data as well as with those reported in the literature. The surface-tension experimental data for the liquid CMSX-4® alloy were found to be close to that of the Al-88.6 at% Ni alloy which is consistent with results from the compound formation model (CFM).

In the framework of its 6th Framework Programme, the European Union funds the Integrated Project IMPRESS, related to industrial applications of Ti-Al and Ni-Al alloys. One central task of this project is the precise determination of the relevant thermophysical properties of selected alloys for both the solid and liquid phases. The properties to be measured include thermal data such as heat of fusion, specific heat, and thermal conductivity, as well as thermophysical and transport properties such as density, surface tension, and viscosity. In addition to conventional high-temperature equipment, containerless methods are used. This article introduces the IMPRESS project, and discusses the first results obtained to date.

The main objective of this work is to determine the wetting behaviour of lead-free solders on copper substrates in view of their applications in electronic industry. The wetting behaviour of X–In–Sn (X=Au, Bi) ternary molten alloys in contact with copper has been studied and compared with the corresponding behaviour of their binary subsystems with a particular attention to the In–Sn/Cu system. The contact angle measurements on Cu-plates were performed by using a sessile drop apparatus. The solder/copper interface was characterised by the SEM-EDS analysis.

Among manufacture techniques for SiC ceramics, reactive infiltration has proven to be the most efficient. However, materials manufactured with this technique present minimum 10% of unreacted silicon. Si hinders the performance of the material. The replacement of Si with a MexSiy can improve the performance of the composite. Since Me–Si alloys wet carbon materials, they are suitable candidates to be used as infiltrants in SiC/MexSiy composite production via reactive infiltration. To optimize the process, it is necessary to identify the mechanisms involved in infiltration and the parameters governing them. A basic wetting study can provide a clear understanding of the operative mechanisms and allow obtaining accurate parameters. In this work, the wetting behavior of silicon-cobalt alloys on carbon materials was studied using the sessile drop technique. The influence of temperature, composition and carbon crystallinity was evaluated, observing a strong dependence of process kinetics and reactivity with temperature and carbon crystallinity. Financial support from the Generalitat Valenciana (PROMETEO II/2014/004-FEDER and PhD grant Vali+d), and the European Union’s Seventh Framework Programme (FP7/2007-2013) under the HELM project, grant agreement no. 280464 are gratefully acknowledged.

In this report, a survey is presented about state-of-the-art thermophysical property measurements of liquid metallic: alloys at high temperatures. Methods for measuring both caloric quantities, like specific heat and thermal conductivity, and thermophysical properties, like density, surface tension and viscosity, are described in detail. Measurement techniques discussed include container-based as well as containerless techniques. Strengths and potential pitfalls in applying these methods are pointed out and recommendations for best-practice are given.

The ThermoLab project is concerned with the measurement of the thermophysical properties of industrial alloys in the liquid phase. The project combines long and short duration microgravità measurements based on containerless processing with an electromagnetic levitation device and a ground based experimental programme using conventional and containerless processing techniques. An overview of the project and representative results from the ground based experimental programme are given. Alloys investigated included Ni-based, Fe-based, a Cu- Sn-Mg alloy and a ³-TiAl alloy.

The wetting phenomena of molten alloy/ceramic substrate depend on the bonding characteristics of liquid alloys and ceramics as well as on the magnitude of interactive forces at the interface. According to this, the first step of this investigation is to determine the surface properties of Ag–Cu, Ag–Ti and Cu–Ti liquid alloys. The energetics of mixing in liquid alloys has been analysed through the study of surface properties (surface tension and surface composition) and microscopic functions (concentration fluctuations in the long-wavelength limit and chemical short-range order parameter) in the frame of statistical mechanical theory in conjunction with the quasi-lattice theory (QLT). The results obtained for these binary systems have been extended to the ternary Ag–Cu–Ti system. Combining the Young and the Dupre equations, the computed results of surface tension together with contact angle data have been used to calculate the work of adhesion and, in the case of non-reactive wetting, the interfacial tension between the solid substrate and the liquid alloys over the whole concentration range. The evaluation of the interfacial tension values is determined from calculated and measured data using solid surface tension data from literature. These results provide more information on the characteristics of metal–ceramic systems, and are therefore useful in guiding experiments, or in predicting the surface properties of metallic systems with similar characteristics as well as their wetting behaviour in contact with ceramic materials.

The surface tension and density of Ni-based superalloys RENE N5(A (R)) and RENE 90(A (R)) have been measured by the pinned drop method at temperatures ranging from 1638 to 1780 K. In order to obtain accurate reliable data, the tests have been performed under a reducing atmosphere to minimize the oxygen contamination. In the temperature ranges investigated, both properties show a linear temperature dependence. With the aim of evaluating the reliability of the data, the present results have been analyzed using different thermodynamic models. The new experimental data for RENE N5(A (R)) and RENE 90(A (R)) superalloys were also compared with the corresponding data obtained by different experimental techniques.

One of the concerns in manufacturing jewellery is the optimisation of gold alloys with regard to their brazability. In jewellery the maintaining of mechanical and metallurgical properties and of the carats of the manufactured jewel after brazing and after re-heating operations has to be considered. These problems were investigated studying the behaviour of three kinds of alloys having 18 K and different melting points. We focused on a new filler metal (i.e. Au-Ag-Zn-Cu) joining two commercial coloured gold based alloys (i.e. Au-Cu-Ag and Au-Cu-Ag-Pd). Several joints, performed in two different geometrical conditions (i.e. butt and superimposed joints), were produced using an air-propane flame as brazing source. The melting range of each alloy was determined by DTA and the wetting parameters between filler and base alloys by the sessile drop method. The joints were radiographed and characterised by optical and scanning electron microscopy, EDS analyses and microhardness HV 0.1 profile. The investigation highlighted the good wetting behaviour of the filler in respect of the two base materials and a satisfactory brazability as confirmed by the absence of metallurgical discontinuities along the brazed zone. The partially superimposed joints, corresponding to the geometrical configuration mainly used in manufacturing jewellery, proved to be more suitable brazing working conditions.

The interactions of liquid metals and alloys with the environment mostly depends on the thermodynamic properties of the liquid surface. In fact, the surface tension is strongly influenced by the presence in the surrounding atmosphere of reactive gases through solution, adsorption mechanisms and/or surface reactions. In particular, oxygen, which shows a high surface activity towards a large number of metallic systems, is the most important contaminant of liquid metals and alloys. Theoretical approaches for estimating the oxygen mass transfer at the liquid–vapour interface under inert atmosphere and vacuum have been developed already in order to relate the observed physical properties to the real surface composition data. In the present work a model of the interfacial transport of a liquid metal–oxygen system under Knudsen conditions that foresees the temporal evolution of the interfacial composition is presented. The diffusion characteristic times for reaching steady-state conditions are evaluated in order to define two system “sizes” depending on the different oxygen transport mechanisms in the liquid phase. An experimental study of the interface evolution is at present under way and preliminary results show a satisfactory agreement with theoretical studies.

In this work, the surface tension and density of Si-Ge liquid alloys were determined by the pendant drop method. Over the range of measurements, both properties show a linear temperature dependence and a nonlinear concentration dependence. Indeed, the density decreases with increasing silicon content exhibiting positive deviation from ideality, while the surface tension increases and deviates negatively with respect to the ideal solution model. Taking into account the Si-Ge phase diagram, a simple lens type, the surface tension behavior of the Si-Ge liquid alloys was analyzed in the framework of the Quasi-Chemical Approximation for the Regular Solutions model. The new experimental results were compared with a few data available in the literature, obtained by the containerless method. (C) 2014 AIP Publishing LLC.

Surface tension of liquid Ag–Cu binary alloys has been measured contactlessly using the technique of electromagnetic levitation in combination with the oscillating drop technique. The measurements were performed at temperatures above the melting point of alloys. The surface tension values were obtained from an analysis of the frequency spectra of droplet oscillations recorded with a CMOS-camera at 400 fps. The alloy samples covered the entire composition range. The surface tension data can be described by linear functions of temperature with negative slopes. The new experimental data were compared to the corresponding theoretical values calculated combining the Butler equation with the ideal and subregular solution models, respectively. The agreement with the experimentally obtained data is excellent for the isothermal surface tension and quite reasonable for their temperature coefficients.