cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.14305971.v1
title: Refractory Ceramics of Clay and Alumina Waste

description: Abstract Refractory ceramics were produced from clays and alumina waste. Specimens were shaped by uniaxial pressing, subjected to thermal analysis by dilatometry and heat-treated in a conventional furnace at 1300 and 1400ºC, applying a heating rate of 5ºC/min and a dwell time of 2 and 3 hours at the maximum temperature. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and physicomechanical properties. The dilatometric analysis before heat treatment indicated that the formulation containing the largest amount of fluxing oxides presented the highest linear shrinkage. The XRD analysis revealed that mullite was the major phase and needle shaped crystals typical of mullite obtained from clay minerals were observed by SEM. The increase in firing temperature and dwell time at the maximum temperature improved the physicomechanical properties of the specimens. The thermal expansion coefficient (TEC) in the range of 25 to 1000ºC varied from 6.2 to 6.9 x 10-6°C-1.
DOI: 10.6084/m9.figshare.14305968.v1
title: Synthesis of the La3Ba5Cu8O18-δ and Sm3Ba5Cu8O18-δ superconductors by the combustion and solid-state reaction methods

description: Abstract In this paper, the synthesis of the La3Ba5Cu8O18-δ and Sm3Ba5Cu8O18-δ superconductors using the combustion method is reported for the first time. Besides, a comparison with the solid-state reaction method was performed. The materials were synthesized at 870 °C for 24 h under oxygen flow. Rietveld refinement showed materials with the main crystal phase corresponding to the orthorhombic structure of space-group Pmm2 (25), with purity in the range 51-85%, which had not reported for the RE358 systems. On the other hand, the magnetic measurements under external fields (30 and 100 Oe) confirmed the diamagnetic response associated with the Meissner effect, and Tc values between 24 and 58 K.
DOI: 10.6084/m9.figshare.14305967.v1
title: On the Influence of Mean Shear Stress on Multiaxial High Cycle Fatigue of Metallic Materials

description: A study has been made of the influence of a superimposed mean shear stress on the capability of some multiaxial high cycle fatigue criteria to predicting fatigue behavior of 42CrMo4 and 34Cr4 alloy steels. Five selected critical plane-based criteria, namely Matake (M), Susmel & Lazzarin (S&L), Findley (F), Carpinteri & Spagnoli (C&S) and Liu & Mahadevan (L&M), were applied to a number of published experimental fatigue resistance limit tests, involving synchronous sinusoidal in-phase and out-of-phase bending and torsion. Applying to the same loading conditions a mesoscopic scale-based criterion proposed by Papadopoulos (P), one could verify that predictive capability of such an approach is almost invariably superior to those associated with the M, S&L, F, C&S and L&M models. As the Papadopoulos criterion is independent of mean shear stress, it seems appropriate to conclude that the inclusion of such a stress as loading parameter in the critical plane-based models does, in fact, exert a negative influence on their predictive capability. Finally, it is worth mentioning that, except for the Matake, S&L and L&M criteria, the other critical plane-based criteria exhibit a dependence of the fatigue resistance in pure torsion with respect to a superimposed mean shear stress, in disagreement with well-established experimental observations.
DOI: 10.6084/m9.figshare.14305965.v1
title: Surfaces, Interfaces and Crystal Growth of Marcasite FeS2

description: Abstract Marcasite mineral is a metastable iron sulphide, α-FeS2, less known and less abundant than pyrite β-FeS2. Their chemical compositions are similar, formed by S22- dimers and Fe2+ species, but the marcasite crystal structure is orthorhombic while pyrite is cubic. The thermodynamic stability of a range of selected surfaces and their kinetic growth are analysed with molecular mechanics simulations implemented in METADISE code. The most stable surface of marcasite corresponds to the (101) surface having the lowest surface energy (marcasite γ 101 = 1.06 Jm-2) and the most favoured kinetic growth rate is expected for the [010] direction (the attachment energy of (010) surface is 0.20 |eV|/at). Mirror twinning is another characteristic of the mineral contributing to a distinctive crystal growth forming different shapes such as striated needles or pseudo-pentagonal flowers. Similarities, differences and overgrowth between the two dimorphs are highlighted.
DOI: 10.6084/m9.figshare.14305964.v1
title: Calcium Silicate-Based Experimental Sealers: Physicochemical Properties Evaluation

description: Abstract The aim of this study was to evaluate physicochemical properties of calcium silicate-based experimental (CS) endodontic sealers, developed using two different vehicles: polyethylene glycol (PG) (CS-PG) or polyethylene glycol associated to chitosan hydrogel (CS-PGCH). TotalFill BC Sealer (TF) and AH Plus (AHP) were evaluated for comparison. Setting time, flow, radiopacity, pH, solubility and volumetric change were analyzed. Data were submitted to ANOVA and Tukey tests with 5% significance level. The CS-PGCH had significantly greater setting time. CS-PG flow was similar to AHP. CS-PG had higher radiopacity than CS-PGCH. Calcium silicate-based sealers presented alkaline pH in all periods. CS-PGCH presented higher solubility in comparison with CS-PG. The volumetric change of CS-PG was similar to TF after 7 days, and to AHP after 30 days. CS-PG presented proper setting time, radiopacity, flow and pH, besides low volumetric change, showing better results than CS-PGCH, and potential for clinical application.
DOI: 10.6084/m9.figshare.14305962.v1
title: Analysis of Processing Parameters to Avoid Additional Oxygen Contamination During Production of Zr-based Bulk Metallic Glasses by Suction Casting in an Arc-melting Furnace

description: This study first reports details of a successful arc-melting furnace in the production of bulk metallic glasses (BMGs). Also, the study presents the results of a statistical experiment evaluating critical processing parameters that can increase oxygen concentration and its effects on the glass forming ability (GFA) of two Zr-based BMGs. The experiments on Zr48Cu46.5Al4Nb1.5 BMG composite found that using low arc-current (200 A), short melting time (11 s), positive pressure of argon inert gas trapped in the synthesis chamber, and the absence of prior melting of a Ti-getter results in a lower oxygen contamination in the produced alloy. The second experiment using the Vitreloy 105 BMG alloy proved the previous findings.
DOI: 10.6084/m9.figshare.14305958.v1
title: Electrolytic Deposition of Ni/NiO on Stainless Steel for Production of Selective Surfaces

description: Abstract The solar energy is one of the most promising energy sources today. In this context, the goal of this work is to produce selective surfaces for receiver tubes of parabolic trough collectors (PTCs). Ideally, solar collectors should have an absorbing surface that has high absorptance for radiation in the solar energy spectrum and, at the same time, low emittance. Therefore, Ni/NiO selective surfaces were produced with Ni in the first film and NiO in the second film. The method used was by electrolytic deposition of nickel on stainless steel AISI 304, followed by oxidation in a muffle furnace. The thicknesses of the coatings were measured with the photometer Digimess, making it possible to verify their variations and the surface irregularities typical of the electrodeposition procedure. The NiO film was observed in scanning electron microscope (SEM). The film hardness was evaluated by the pencil hardness test and the adhesion by the tape test.
DOI: 10.6084/m9.figshare.14305956.v1
title: The Chalcogenide Compound Fe2SnSe4: Synthesis and Crystal Structure Analysis by Powder X-ray Diffraction

description: Abstract Fe2SnSe4 belongs to the adamantine family of quaternary chalcogenides crystallizing in the olivine type structure, which can be described from a hexagonal close-packing of selenium anions with the octahedral and tetrahedral sites occupied by the iron and tin cations, respectively. The structural characterization of the sample, synthesized by the melt and annealing technique, was carried out by powder X-ray diffraction at room temperature. The XRD data analysis shows, that Fe2SnSe4 adopt the orthorhombic olivine type structure, space group Pnma, and unit cell parameters a = 13.2019(3) Å, b = 7.6746(1) Å, c = 6.3572(1) Å, V = 644.11(2) Å3 were derived.
DOI: 10.6084/m9.figshare.14305953.v1
title: Application of Nanometer Antimony Trioxide Modified by Dioctyl Phthalate in Polyvinyl Chloride Flame Retardant Materials

description: In order to improve the compatibility and dispersion of antimony trioxide nanoparticles (nano-Sb2O3) in polyvinyl chloride (PVC) and improve the comprehensive properties of PVC, a novel type of nano-Sb2O3/DOP/PVC composites was prepared by using nano-Sb2O3 modified by dioctyl phthalate (DOP) as flame retardant and the mechanical properties and flame-retardant properties of the composites were studied. The results indicated that nano-Sb2O3 particles modified by appropriate DOP could improve the flame retardancy and tensile strength of PVC matrix composites due to good dispersibility and interface compatibility of nano-Sb2O3 in PVC matrix. The PVC matrix composites containing 2 wt% nano-Sb2O3 particles modified by DOP with 5 wt% of usage had excellent flame retardancy, which LOI was 29.8% and its UL94 grade was V-0 level. And the heat release rate,smoke production rate, CO content and CO2 content of the composites was significantly reduced. Meanwhile, the tensile strength and Young's modulus of the composites were 15.9 MPa and 2.1 GPa, respectively.
DOI: 10.48370/ofd/evra1y
title: Botrytis globosa A. Raabe, 2734

description: Fungarium Mikromycetes
DOI: 10.6084/m9.figshare.14305950.v1
title: 45S5 Bioglass-Derived Glass-Ceramic Scaffolds Containing Niobium Obtained by Gelcasting Method

description: Scaffolds of bioglass derived from BG45S5 (45 wt% SiO2, 24.5 wt% CaO, 24.5 wt% Na2O and 6 wt% P2O5) containing 10 wt% niobium were prepared by gelcasting method. The scaffolds presented a 3D porous structure with interconnected and spherical pores (pore size range 100 μm to 500 μm) and high porosity (89%), similar to trabecular architecture of spongy bone. The compressive strength was 0.18 ± 0.03 MPa which is acceptable for bone repair applications. The in vitro biological studies showed cytocompatibility for human osteoblastic cells as well tendency for higher alkaline phosphatase activity. Therefore, the findings here suggest the great potential of the scaffolds for using in bone tissue engineering.
DOI: 10.6084/m9.figshare.14305947.v1
title: New ASPN High Efficiency Treatment of ASTM M2 Steel

description: Abstract Plasma nitriding treatments are applied to achieve excellent surface properties on steel parts and tools. Active screen plasma nitriding (ASPN) does not have the defects presents in direct nitriding plasma treatments (DCPN). However, ASPN require much longer processing times to develop surface layers as deep as those of DCPN. This work presents the development of a biased ASPN treatment system, to investigate the possibility of achieving greater efficiency. The treatments were performed on ASTM M2 steel samples using the same processing parameters in 4 different configurations: DCPN, ASPN and 2 active screen plasma nitriding with biased specimens voltage: one was called "bright bias", because biased voltage is high enough to develop a plasma glow on the samples, and the other "dark bias", where no plasma glow sheath is seen on the samples. The active screen dark biased treatment presented the best results. These results could be understood by the electromagnetic field generated by the bias source promoting the deposition of nitrogen ions on the surface of the part being treated. Therefore, it was demonstrated that the use of dark bias voltage in the active screen treatment in larger reactors is fundamental to achieve good nitriding results in smaller times.
DOI: 10.6084/m9.figshare.14305945.v1
title: Comparative Study Between Sensitization Degree of the 0.4% Mo Austenitic Stainless Steel and UNS S31803 Duplex Stainless Steel

description: This study aims at assessing the degree of susceptibility to intergranular corrosion of the UNS S31803 duplex stainless steel and the 0.4% Mo austenitic stainless steel through the double-loop electrochemical potentiodynamic reactivation (DL-EPR) test. Both steels were subjected to isothermal treatments at 650ºC and 900ºC in order to compare the effect of temperature on the respective degrees of sensitization. It was observed that the 0.4% Mo austenitic stainless steel presented a higher degree of sensitization and, consequently, a greater susceptibility to the intergranular corrosion process when compared to the UNS S31803 duplex stainless steel in the two temperatures studied. It was also observed that, for both steels, the heat treatment at 900ºC resulted in a higher degree of sensitization when compared to the heat treatment at 650ºC.
DOI: 10.6084/m9.figshare.14305944.v1
title: Influence of Hastelloy’s Cathodic Cage Plasma Deposition on Corrosion Resistance of AISI 304 Stainless Steel and of AISI D6 Tool Steel

description: Abstract AISI D6 tool steel and AISI 304 stainless steel are among the most widely used material in the industry. However, this application field can still be expanded through the coatings deposition. In this regard, the objective of this work was to evaluate the impact of coatings application by cathodic cage technique using Hastelloy’s cathodic cage, on corrosion resistance of these steels. Two treatment temperatures were compared. The samples were characterized by Optical Microscopy, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-Ray Diffraction with the application of the Rietveld routine and corrosion test. The results showed the formation of multiphase layers that contributed to corrosion potentials reduction for treatments at 400 °C, being more effective when applied on AISI D6. It was observed that the corrosion resistance is influenced by the temperature, which was attributed to the precipitation of chromium nitride and iron oxide at 450 ºC.
DOI: 10.6084/m9.figshare.14305941.v1
title: The role of ERNi-1 wire on Microstructure and Properties of Pure Nickel N6 Plasma Arc Welding joint

description: Abstract The butt welding tests of 5.5mm thick pure nickel N6 plate were carried out by plasma arc welding (PAW) and ERNi-1wire-filled PAW. And the differences in microstructure and properties between two kinds of joints were studied. The results show that the wire-filled pure nickel N6 joint has good appearance without defects such as pores, cracks, and undercuts. Pure nickel N6 weld is single-phase austenite structure, and no phase transformation occurs during heating or cooling. The weld zone of PAW joint is characterized by coarse columnar grain with average grain size of 125.8 μm, while the weld zone of wire-filled joint is equiaxed grain with average grain size of 54.8 μm. The tensile strength of the wire-filled PAW joint is 337MPa and the elongation after fracture is 44%, which is 11.6% and 85.5% higher than that of the PAW joint. The corrosion rate of wire-filled PAW joint is 2.6908g/m2h, which is lower than that of PAW joint of2.8820g/m2h, and the corrosion rates of both joint are higher than the base metal. The alloy elements in the welding wire can supplement the alloy elements burned in the welding process. As the filler metal, the melted wire forms the joint with the melted base metal, avoiding the defects such as undercut and depression. Al and Ti elements in ERNi-1 wire have deoxidation and nitrogen fixation effect during welding thermal cycle process, which improves the resistance of weld to carbon monoxide and nitrogen porosity. In the process of nitrogen fixation, TiN particles are formed in the crystal or grain boundary. TiN particles at the grain becomes heterogeneous nucleation particles in the grain, which makes a large number of nucleation and increases the nucleation rate. TiN particles at grain boundaries act as "nails" to hinder the migration of austenite grain boundaries. In the deoxidization process, the deoxidized products Al2O3 and TiO2 are formed. However, large-size inclusions are formed owing to the high content of Al and Ti in the molten pool, which affects the performance of the joint. Therefore, the structure and performance of filler wire-filled PAW joint are better than those of PAW joint.
DOI: 10.6084/m9.figshare.14305940.v1
title: Selective Surfaces of Ilmenite for Use in Solar Absorbers

description: Abstract The world is moving at a fast pace in the consumption of non-renewable natural resources, causing several ecological problems. The search for the cost reduction by implementing renewable energies implies in the optimization of the manufacturing processes parameters of consolidated technologies, such as solar thermal energy collectors. One of the applications of selective surfaces is to improve performance of solar absorbers. The purpose of this work is to produce selective coatings with high absorption in range of UV/Vis and low emittance in the IR range. It was prepared a selective surface composed of ilmenite deposited on substrates of AISI 304 stainless steel using technique of cathodic cage plasma nitriding/deposition for application in solar thermal absorbers. Ilmenite was initially characterized by X-Ray Diffractometry (XRD), X-Ray Fluorescence (FRX) and Thermal Analysis (TGA). The coatings produced were optically characterized in range UV/Vis/IR and emittance and data on the roughness parameters of the films were obtained by Optical Profilometry. Selective surfaces with high solar absorbance (87%) compared with state-of-the-art commercial ones (70-80%) and low thermal emission (14%) compared with state-of-the-art commercial ones (20-30%) were obtained by validating the potential of ilmenite to produce selective surfaces for thermal solar collectors.
DOI: 10.6084/m9.figshare.14305938.v1
title: Analysis of Microsegregation in Al-Si-Cu Ternary Alloys: Interdependence of Solute Composition at the Solubility Limit during Non-Equilibrium Solidification

description: Abstract Virtually all metals used industrially undergo a solidification process during their production. Depending on the material and its manufacturing process, its physical/mechanical properties are affected to a greater or lesser extent by the microstructure and microsegregation obtained during the phase change. Aluminum casting alloys are good examples of products where this microstructure is vital for obtaining the desired properties. A sequence of experiments to analyze the upward vertical unidirectional solidification with transient heat transfer conditions in Al-Si-Cu ternary alloys was developed in the present work. The experimental results obtained were compared with classical microsegregation models. Discrepancies related to their use for ternary alloys were raised. Since the calculated results by these models do not take into account the influence of one alloying element on the solubility of the other element, disparities were founded between experimental and numerical results. A microsegregation model was proposed based on the solubility limits of the Si in the alloy as a function of the Cu concentration present in the liquid. The model, combined with the concepts of classical microsegregation theory, allows a realistic description of the microsegregation phenomenon. The model showed an excellent agreement between microsegregation profiles of solute experimentally measured and calculated.
DOI: 10.6084/m9.figshare.14305936.v1
title: Structure, mechanical properties and oxidation resistance of iso and non-iso architected TiN/Cr multilayers coatings deposited by magnetron sputtering

description: Abstract Iso and non-iso architected TiN/Cr multilayers with constant composition were deposited by balanced magnetron sputtering aiming to investigate the influence of different architectures over coatings structures and properties. Glow discharge optical emission spectroscopy analyses were used to determine in-depth constituents and suggested that no diffusion of elements occurred between layers in room temperature. Field emission gun scanning electron microscopy analyses showed that all multilayers presented sharp interfaces and low porosity microstructures, with column-like grain growth influenced by layer sizes. Glancing angle X-ray diffraction analyses showed that multilayers consist of polycrystalline α-Cr and δ-TiN phases with a main peak in Cr(110) plane. The overlapping of TiN onto metallic layers led to the suppression of growth in the TiN(111) plane, although TiN layers thicker than 50 nm demonstrated a growth in plane TiN(200). Nanoindentation tests registered equal hardness values for all multilayers of around 16.2 GPa, on the other hand, a tendency to improve hardness has been identified for hierarchical multilayer. Oxidation tests revealed that architectures with thicker TiN top layers presented an improved oxidation resistance up to 600 ºC, probably due to growth in more compact TiN(200) plane. However, TiN/Cr coatings did not resist integrally to oxidation tests at 750 ºC.
DOI: 10.6084/m9.figshare.14305934.v1
title: Oxidation of AISI 304L and 348 Stainless Steels in Water at High Temperatures

description: Oxidation of AISI 304L and 348 stainless steels was investigated in water at 1000 – 1350 °C by TGA, SEM, EDS, and Raman spectroscopy. Linear-Parabolic kinetics and multilayer oxide scales with voids were found for both alloys. Based on the experimental results, AISI 304L presented higher oxidation resistance and higher activation energy. Zircaloy-4 kinetic results were used for validation and performance comparison. In severe accidents conditions, stainless steel might lead to a faster hydrogen production comparing to Zircaloy.
DOI: 10.6084/m9.figshare.14305928.v1
title: Structures and Properties of KxCryNi1-x-yO Dielectric Materials Prepared by an Ultrasonic-Assisted Sol-Gel Method

description: Abstract KxCryNi1-x-yO (x = 0.05-0.20, y = 0.02) dielectric materials were prepared using a facile simple green ultrasonic-assisted sol-gel method. All samples have a main phase consisting of a cubic NiO structure and with nanoscale crystallite sizes (28.58-37.51 nm). However, secondary phases were also observed for the samples with x values exceeding 0.10. The fractured surface microstructures of the samples with x values less than 0.15 exhibited uniformly distributed spherical grains. Other samples showed irregularly shaped grains. The grain sizes were larger when x was increased to 0.15 and exhibited increased grain growth probably due to substitution of K ions into the NiO lattice. However, a reduction of grain sizes was observed in the sample with x = 0.20, possibly due to inhibition of the grain growth by the secondary phase. At room temperature and a frequency of 1013 Hz, the highest dielectric constant of 2.25 × 104 was obtained for the samples with x = 0.15.