Evolution Of Physical Properties Research Articles

Evolution of microstructure and physical properties of lead-free Sn–5Sb-Ag rapidly solidified solder alloys

Rapidly solidified (RS) binary Sn–5 wt.% Sb and ternary Sn–5 wt.% Sb– x wt.% Ag, x = 1, 3 and 5 solder alloys were prepared in form of ribbons using melt spinning technique (MS). X-ray diffractometer (XRD), scanning electron microscopy (SEM) attached with energy dispersive x-ray technique (EDX) and differential scanning calorimetry (DSC) were used to investigate the impacts of Ag contents on microstructures and properties of the binary Sn–5 wt.% Sb rapidly solidified alloy. XRD analysis confirmed the formation of an ultrafine microstructure of Ag3Sn intermetallic compound in addition to a supersaturated solid solution of Sn by Sb and Ag. Moreover, SEM and EDX analysis assigned the formation of SnSb intermetallic compound as well as the dissolution of Sb and Ag in β-Sn with maximum wt.% of 20.75 and 11.7 for Sn-5Sb and Sn-5Sb-5Ag ribbons, respectively. The melting point of the melt spun ribbons was lowered by 3.7 °C, 1.7 °C, 5.4 °C and 2.3 °C for the 0, 1, 3 and 5 Ag containing solder alloys as deduced by DSC. The rapidly solidified ribbons exhibit better Vickers hardness due to the microstructure refinements and the extension of solid solubilities of the alloying elements.

Evolution of microstructure, strain and physical properties of quaternary nanoparticles La0.8−xCexAg0.2MnO3 perovskites

Evolution of microstructure, strain and physical properties of quaternary nanoparticles La0.8−xCexAg0.2MnO3 perovskites

The Relationship between Diagenetic Evolution and Hydrocarbon Charge in Deep Tight Reservoirs: A Case Study from Kepingtage Formation of S9 Well Block in Tarim Basin

The Silurian Kepingtage Formation of Tarim Basin is an important deep clastic reservoir. Exploration practice shows that the reservoirs are generally characterized by extremely low porosity and permeability, exhibiting strong mineral composition and physical property heterogeneities. The study of heterogeneity and its effect on oil charge is of great significance to the understanding of oil migration and accumulation in such reservoirs and thus is crucial to oil exploration. Therefore, based on identification and quantitative statistics of thin sections, SEM, and homogenization temperature measurements, this study was designed to examine the relationship between diagenetic evolution and oil emplacement in the Silurian Kepingtage Formation in S9 Block in Tarim Basin. The control of differential diagenesis and physical property evolution on oil charge process are discussed. It is found that the sandstones with fine grain size and high content of ductile grains (>20%) have experienced strong mechanical compaction, the porosity decreases rapidly in the early stage of burial. The densification process has been completed before the first period of oil charge so that no oil was found in the reservoir. In contrast, sandstones with relatively coarse grain size and low ductile grain content have better porosity and permeability properties, which are generally oil-bearing. This kind of sandstone generally experienced two periods of oil charge. Apart from moderate compaction, multiple diagenesis events were also observed, including quartz cementation, calcite cementation, and dissolution. Before the early period of oil charge, the diagenesis events are dominated by moderate compaction, chlorite cementation, and dissolution, and the reservoir property is still high. It seems that the time of late period oil charge is relatively long. With the growth of multiple types of authigenic minerals such as quartz, calcite, and illite after or sometimes synchronously occurred with the late period oil charge, the porosity gradually decreases.

Pore structure, adsorptivity and influencing factors of high-volatile bituminous coal rich in inertinite

Bituminous coal rich in inertinite is widely distributed throughout the world, but the effect of the first coalification jump (FCJ) on the reservoir properties of high-volatile bituminous coal rich in inertinite, has rarely been studied. Therefore, nine coal samples were collected from the southwestern Ordos Basin and used in a series of experiments designed to study the adsorptivity of high-volatile bituminous coal rich in inertinite and factors affecting adsorptivity before and after FCJ. Such information is helpful for further understanding the evolution of coal physical properties in the key stage of early coalification. The pyrolytic parameters indicate that the FCJ of the coal samples was between 0.60% and 0.65% (Rr). The NMR-T2 spectrum type of the samples was bimodal differentiation before FCJ, and after FCJ, it was a bimodal connection or adsorption single peak. The fractal dimension of adsorption pore increased with increased Rr and inertinite content. The adsorptivity of coal were affected by coalification and macerals. Langmuir pressure was mainly controlled by the maceral composition and exhibited a positive linear relationship with the ratio of vitrinite to inertinite. Langmuir volume was mainly controlled by maceral composition, and coalification, before and after FCJ, respectively. The increase in the adsorption pore volume of high-volatile bituminous coal caused by the increase in inertinite content had little effect on the increase in the adsorption capacity of the coal. In the stage of high-volatile bituminous coal, bitumen is adsorbed by vitrinite, which blocks and fills the pores of vitrinite, thereby reducing the adsorption capacity of coal.

Physical Property Evolution of the Anode Mixture during the Baking Process.

The Hall-Héroult process uses prebaked carbon anodes as electrodes. The anode’s quality plays a crucial role in the efficiency of the aluminium production process. During the baking process, the anode undergoes complex physicochemical transformations. Thus, the production of high-quality anodes depends, among others, on the efficient control of their baking process. This paper aims to investigate the evolution of some physical properties of the anode paste mixture during the baking process. These properties include the mass loss fraction, real and apparent densities, the ratio of apparent volume, the permeability, and porosities. For this purpose, experiments consisting of thermogravimetric analysis, dilatometry, air permeability, and helium-pycnometric measurements were carried out. The anode permeability at high temperatures was linked to the air permeability through a permeability correlator due to experimental limitations. Moreover, the real density at high temperatures was estimated by combining real densities of the coal tar pitch and coke aggregates. Different porosities, such as the open porosity and the closed porosity related to the pitch binder, were estimated by taking the permeability at high temperatures into account. In this context, the effect of the permeability correlator, which was introduced to link the permeability at high temperatures to the air permeability, was investigated through a sensitivity analysis. These results allow an estimation of the shrinking index, a new variable introduced to reflect the baking level of the anode mixture, which is linked to the volatile that is released in both open and closed pores. Afterwards, the pore pressure inside closed pores in the coal tar pitch was estimated. The obtained results highlight some new insights related to the baking process of the anode mixture. Moreover, they pave the way for better modeling of the thermo-chemo-mechanical behavior of anodes at high temperatures.

Experimental and Theoretical Investigations of Hard Rocks at High Temperature: Applications in Civil Engineering

This review paper aims to survey and discuss recent theoretical and experimental works reporting the temperature effects on the mechanical properties of rocks like granite, gabbro, gneiss, marble, sandstone, basalt, limestone, and argillite to permit the new challenge in this domain. The effect of high temperatures on various mechanical and physical material properties (Young’s modulus, porosity, tensile and compressive strengths, P‐wave velocity, permeability, thermal damage, and expansion) is analyzed. This work shows that hard rock mechanical and physical properties evolutions are strongly related to the evolution of the microstructure caused by the geological history, cracks nucleation occurrences, recrystallization, dehydroxylation, and dehydration reactions. However, it should be emphasized that these studies were not conducted on all types of intrusions and all rocks types. Meanwhile, it has been noticed that variations in temperature could lead to contradictory phenomena. Therefore, different trends were observed for the evolution of physical properties of rocks. There is an increase in porosity approximately 80% above 500°C. In general, for volcanic’s rock, the loss mass and thermal conductivity were drastically observed at low temperatures around 200°C with an antinomic phenomenon. Sandstone, granite, and argillite present the model whose behaviors with thermal load are too much explored accordingly with experiments compared with other rocks. Argillite at 200°C and sandstone and granite at 400°C undergo seriously damage. There is 100°C gap between the results obtained in real‐time and those obtained after cooling. Moreover, 300°C can be considered as the critical temperature for real‐time temperature heat treatment at which rocks lose almost about 80% of their performance. Otherwise, it is not easy to predict the behavior at high temperature of volcanic rocks like basalt and metamorphic rocks like gneiss which present the complexity in their behavior. For plutonic and metamorphic rocks, 600°C is the critical thermal load. At this temperature, the modulus of elasticity as well as the compressive strength of the most explored rock shows a significant decrease of about 75% for hard rocks. In sum, high temperature damages significantly the mechanical performance of rock. It is the reason for which these results may be useful to characterize the damage and thus predict the dramatic consequences of large temperature fluctuations on engineering structures in the rock.

The impact of landscape evolution on soil physics: evolution of soil physical and hydraulic properties along two chronosequences of proglacial moraines

Abstract. Soil physical properties highly influence soil hydraulic properties, which define the soil hydraulic behavior. Thus, changes within these properties affect water flow paths and the soil water and matter balance. Most often these soil physical properties are assumed to be constant in time, and little is known about their natural evolution. Therefore, we studied the evolution of physical and hydraulic soil properties along two soil chronosequences in proglacial forefields in the Central Alps, Switzerland: one soil chronosequence developed on silicate and the other on calcareous parent material. Each soil chronosequence consisted of four moraines with the ages of 30, 160, 3000, and 10 000 years at the silicate forefield and 110, 160, 4900, and 13 500 years at the calcareous forefield. We investigated bulk density, porosity, loss on ignition, and hydraulic properties in the form of retention curves and hydraulic conductivity curves as well as the content of clay, silt, sand, and gravel. Samples were taken at three depths (10, 30, 50 cm) at six sampling sites at each moraine. Soil physical and hydraulic properties changed considerably over the chronosequence. Particle size distribution showed a pronounced reduction in sand content and an increase in silt and clay content over time at both sites. Bulk density decreased, and porosity increased during the first 10 millennia of soil development. The trend was equally present at both parent materials, but the reduction in sand and increase in silt content were more pronounced at the calcareous site. The organic matter content increased, which was especially pronounced in the topsoil at the silicate site. With the change in physical soil properties and organic matter content, the hydraulic soil properties changed from fast-draining coarse-textured soils to slow-draining soils with high water-holding capacity, which was also more pronounced in the topsoil at the silicate site. The data set presented in this paper is available at the online repository of the German Research Center for Geosciences (GFZ; Hartmann et al., 2020b). The data set can be accessed via the DOI https://doi.org/10.5880/GFZ.4.4.2020.004.

Temperature-Time profile effects on evolution of physical and electronic properties in visible light Cu2CoSnS4 photodetectors

Earth-abundant quaternary chalcogenide Cu2CoSnS4 (CCTS) films on soda-lime glass (SLG) substrates are prepared via non-vacuum, cost-effective direct solution spin coating technique. The phase formation mechanism of CCTS films is investigated via TGA, FTIR, XRD, and RAMAN characterization. Annealing temperature effects on the crystalline phase, chemical composition, and grain growth, strongly linked with electrical and photodetection parameters of CCTS films, are systematically investigated through XRD, Raman, FEG-SEM, and EDS analysis. Through the transfer length measurement (TLM) method, the electrical properties of CCTS films annealed at 575 °C exhibit noticeable 92% reduction of both contact resistance (Rc) and resistivity (ρ), compared to those of the film processed at 300 °C. The highest photoresponsivity (7.50 A/W) and specific detectivity (4.70 × 1010 Jones) of CCTS devices have been demonstrated with annealing conditions at 575 °C and a bias voltage of 10 V as well. The present study reveals the impact of both annealing temperature and bias voltage on photodetector performance.

Physical properties evolution in carbon foams as function of synthesizing temperature

Carbon foams obtained with Pyroligneous acids from a carbon precursor, such as guadua (angustifolia kunth), were obtained by the blow foaming method at different carbonization temperatures. Physical properties of carbon foams obtained from pyroligneous acids from guadua (angustifolia kunth) were analyzed as a function of the synthesization temperature due to that the carbon foams were obtained by the blow foaming method at different carbonization temperatures. To analyze the temperature’s influence on the crystallographic properties, chemical composition, microstructural characteristics and mechanical properties, the carbon foams were characterized by X-ray diffraction techniques (XRD), energy dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The mechanical properties were analyzed by stress-strain tests which are associated with maximum stress. The current work demonstrates the evolution of mechanical properties of the carbon foams, showing greater linear region modulus Es of around 45.8%, Beam module, yield stress (σe) (elastic limit) and fracture stress (σpl) (plastic limit) by the foam obtained at 700 °C. Moreover, the adsorption tests of methylene blue were also performed with the foams which were analyzed with the Uv–vis visible ultraviolet spectroscopy technique. The current work demonstrates the ability of the carbon foams to absorb and filter the methylene blue dissolved in water evidenced by adsorption tests. Taking into account the above, the results of this research opens the possibility of obtaining carbon foams that can be applied in water filters.

A Practical Review of the Laser-Heated Diamond Anvil Cell for University Laboratories and Synchrotron Applications

In the past couple of decades, the laser-heated diamond anvil cell (combined with in situ techniques) has become an extensively used tool for studying pressure-temperature-induced evolution of various physical (and chemical) properties of materials. In this review, the general challenges associated with the use of the laser-heated diamond anvil cells are discussed together with the recent progress in the use of this tool combined with synchrotron X-ray diffraction and absorption spectroscopy.

Physical and Mechanical Property Evolution of Jute and E-glass fiber Hybrid PMC'S

Now a day’s Natural Fibres Composites owing importance due to its Bio degradability, Light weight& Strength etc ., This project aims to investigate Mechanical Property evaluation of Jute fibre Eglassfiber, without chemical treatment and applied an compression load on the Jute fibre layers to be in uniform and Unidirectional. To evaluate the mechanical properties and weights of specimens are2 and 3 layeerstaken, Epoxy & Hardener constant for all specimens. The Specimens prepared by Hand layup technique and specimen cuts with Manual Hacksaw frame and applied smooth filing to avoid notches during cutting. Testing’s for Mechanical properties evaluation used are tensile, and 3-Point Flexural testing’s on computerized UTM (INSTRON 3369). Hardness and Impact tests also performed per the ASTM standards.

Physical property evolution of granite during experimental chemical stimulation

The Soultz-sous-Forêts geothermal reservoir (France)—in particular, the GPK-4 well—has been proposed as a target for chemical stimulation under the DESTRESS Horizon-2020 framework. With a combination of batch reaction tests and acid flow-through experiments using hydrochloric acid (HCl) at different molarities and temperatures, we investigate the potential for acid-induced permeability enhancement of a granite analogous to the Soultz-sous-Forêts reservoir rock, by means of acid stimulation. In the batch reaction experiments, we find that the propensity for increase or decrease in porosity and permeability depends on the physico-chemical properties of the starting material: unaltered granite underwent a significant increase in both porosity and permeability relative to its initial state, altered granite exhibited a moderate increase in both porosity and permeability (modulated slightly by HCl molarity), whereas initially more porous and permeable thermally and naturally fractured granite exhibited an increase in porosity accompanied by a relative decrease in permeability. The extent to which permeability increased or decreased appears to be tied to the initial fluid-flow characteristics of the material. Using a new, custom-built acid permeameter, flow-through tests were performed on unaltered granite, while the acid was sampled at regular time intervals. Element release into solution recorded throughout the experiments, indicated dissolution of granite minerals. Despite this operative micromechanism, however, the absolute change in sample permeability is limited, both at room temperature and at 100, ^{circ } hbox {C}. Ultimately, these data suggest that the potential for geothermal reservoir enhancement using HCl is low at Soultz-sous-Forêts. Nevertheless, the possibility remains that a more targeted thermal or chemical stimulation approach—or hybrid thereof—could prove effective in the future.

Correlation of Local Crystal Structural and Physical Properties of the Delafossite CuCr1-xFexO2 (0 ≤ x ≤ 1) Series.

Cu-based delafossites offer multifunctional properties that include electrical, magnetic, optical, and thermal transport, and they also act as a photocathode for energy-harvesting applications. Such properties can be modified by bringing about subtle changes in the chemical environment, like introducing holes or excess electrons in the system. With the aim to understand the evolution of physical properties that take place upon systematically replacing 3d3 (Cr3+) with 3d5 (Fe3+), we performed a comprehensive study of structural, electrical and thermal transport, and magnetic properties of the CuCr1-xFexO2 series. In agreement with the different ionic radii of trivalent cations, high-intensity X-ray diffraction confirms a systematic increase of the unit cell parameters. Extended X-ray absorption fine structure spectroscopy confirms the uniform solution of mixed trivalent Cr3+/Fe3+ cations and demonstrates the changes in the hybridization between Cu 3d and O 2p orbitals. Cu K-edge near-edge spectra reflect a sharp 1s → 4p transition associated with the ligand-metal charge transfer "shakedown" process in the collinear O-Cu-O bond along c-axis, whereas the Cr and Fe K-edge absorption spectra show small reciprocal shifts in the edge energies. The charge carrier concentration increases with Fe substitution as confirmed from Hall effect measurement; both p-type conduction and a decrease in the electrical resistivity are observed. The electrical conduction follows a 3D variable range hopping at low-temperature and thermally activated transport at high temperature. The two end members of the series are well-studied, geometrically frustrated antiferromagnetic systems; the present study of magnetic properties of intermediate compositions show a systematic increase of FM interaction with rising Fe concentration and hence a competing magnetic state. A sharp transition in high-temperature (600 K) region identifies a truly paramagnetic state for Fe rich compounds. Thermal conductivity values are drastically affected by the spin fluctuation and spin-phonon scattering taking place in these compositions.

Eco-Friendly Fully Water-Driven HfGdO${_{x}}$ Gate Dielectrics and Its Application in Thin-Film Transistors and Logic Circuits

In this work, HfGdO x gate dielectric thin films have been prepared via a nontoxic and environmental-friendly fully water-driven (WD) method. An in-depth investigation has been conducted to reveal the evolution of physical properties in the as-prepared HfGdO x thin films as a function of annealing temperature. Based on the measurements of electrical parameters of the HfGdO x thin films, it is observed that the 500 °C-annealed HfGdO x thin films have shown optimized properties, including a smooth surface, lower leakage current density, and a larger areal capacitance. To validate the feasibility of the HfGdO x gate dielectrics in thin-film transistors (TFTs), In2O3/HfGdO x TFTs have been constructed. The optimized In2O3/HfGdO x TFT exhibited excellent electrical performances, including high field-effect mobility of 11.2 cm2 V−1 s−1, a high ON-/OFF-state current ratio of ${4.1} \times {10}^{{6}}$ , a small sub-threshold swing of 105.2 mV/decade, and a threshold voltage shift of 0.58 V after 7200-s bias stress, respectively. Finally, based on the In2O3/HfGdO x TFT, an inverter is assembled by connecting an external 3- $\text{M}\Omega $ resistor. High gain of 8.73 and excellent swing characteristics have been obtained. As a result, it can be inferred that fully WD In2O3/HfGdO x TFTs with high performance will pave the way for achieving low-power-consumption, low-cost, and large-area electronics.

Synthesis, Dehydroxylation and Sintering of Porous Mg(OH)2-MgO Clusters: Evolution of Microstructure and Physical Properties

Abstract: Magnesium hydroxide (Mg(OH)2 or brucite) and magnesium oxide (MgO or magnesia) are essential raw materials for many industrial applications. Several studies have explored their production methods and the changes in their properties caused by adjustments in synthesis and calcination conditions. However, the ways the particles' microstructure changes along a full thermal treatment up to sintering remain unclear. This study investigated the effects of thermal treatments (120-1500 °C) on the physical properties and microstructure of clusters of Mg(OH)2 nanoparticles prepared by soluble-Mg-salt precipitation assisted by a surfactant agent.

Evolution of Physical and Mechanical Properties of Al5083/B4C Composites fabricated through Stir Casting

Abstract In the present work, Aluminium composites were fabricated through conventional stir casting process. The composites were fabricated at 800°C inside the electric furnace in the presence of inert gas. AA5083 and B4C particulates with varying weight % of 5, 10, 15 and 20 were used as the starting materials. The microstructure of the composites was examined using scanning electron microscopy (SEM). The physical and mechanical properties of the composites were investigated and the results show that the increase in B4C content in the aluminium matrix increases the tensile strength and hardness of the composites to a significant level. The decrease in density accompanied by increase in porosity was also observed with the increase in B4C.

High-resolution spectropolarimetric observations of the temporal evolution of magnetic fields in photospheric bright points

Context. Magnetic bright points (MBPs) are dynamic, small-scale magnetic elements often found with field strengths of the order of a kilogauss within intergranular lanes in the photosphere. Aims. Here we study the evolution of various physical properties inferred from inverting high-resolution full Stokes spectropolarimetry data obtained from ground-based observations of the quiet Sun at disc centre. Methods. Using automated feature-tracking algorithms, we studied 300 MBPs and analysed their temporal evolution as they evolved to kilogauss field strengths. These properties were inferred using both the NICOLE and SIR Stokes inversion codes. We employ similar techniques to study radiative magnetohydrodynamical simulations for comparison with our observations. Results. Evidence was found for fast (∼30−100 s) amplification of magnetic field strength (by a factor of 2 on average) in MBPs during their evolution in our observations. Similar evidence for the amplification of fields is seen in our simulated data. Conclusions. Several reasons for the amplifications were established, namely, strong downflows preceding the amplification (convective collapse), compression due to granular expansion and mergers with neighbouring MBPs. Similar amplification of the fields and interpretations were found in our simulations, as well as amplification due to vorticity. Such a fast amplification will have implications for a wide array of topics related to small-scale fields in the lower atmosphere, particularly with regard to propagating wave phenomena in MBPs.

Hydrate growth in quartzitic sands and implication of pore fractal characteristics to hydraulic, mechanical, and electrical properties of hydrate-bearing sediments

Gas hydrate pore habits significantly impact the pore-scale structure within hydrate-bearing sediments, and thus, play a central role in the physical property evolution. Characterization and quantification of the effective pore space within hydrate-bearing sediments at different hydrate saturations have not been well offered. This study performs random simulations of hydrate nucleation and growth in quartzitic sands to understand effects of hydrate saturation and hydrate pore habits on fractal characteristics of the effective pore space. Normalized pore-size fractal dimension and normalized maximal pore diameter are characterized and found to decrease with increasing hydrate saturation. In order to predict hydrate saturation dependent pore fractal characteristics, theoretical and empirical models are proposed and further extended to give implications to hydraulic, mechanical, and electrical properties of hydrate-bearing sediments during hydrate dissociation. Implications include that hydrate dissociation facilitates the absolute permeability and the electrical conductivity, and enhances first and then reduces the saturation exponent of Archie's law; hydrate dissociation also lowers the capillary pressure, and this promotes relative permeability to gas but inhibits relative permeability to water even the water saturation remains as a constant; shear strength of unsaturated hydrate-bearing sediments drops down due to the decreasing capillary pressure as hydrate dissociation. These implications all meet with conclusions in previous literatures.

Study on soot evolution under different hydrogen addition conditions at high temperature by ReaxFF molecular dynamics

The physical and chemical properties evolution of soot particles was studied by ReaxFF MD simulation. The dimerization of PAHs, nucleation and coagulation, and graphitization from hydrocarbons to the final soot nanoparticle were investigated, and the chemical effects of the hydrogen addition on the formation mechanism of primary soot nanoparticle was explored by considering important polycyclic aromatic hydrocarbons (PAHs) in ethylene flames under high temperatures. The results obtained reveal that, in the first stage, the activated aliphatic hydrocarbons mainly grow into a large ring through the chain growth reactions, and then gradually form PAH-like molecules with inner ring bridging instead of directly generating the five or six-carbon ring structures. Hydrogenation effectively inhibited the soot nanoparticle nucleation at all stages. Due to a large number of vinyl and acryl groups attacked by the hydrogen to decarbonize and produce methane, a rapid decrease of the formation and growth rate of the PAHs was observed. With the increase of hydrogen, the nucleation and surface growth rate of soot particles are slowed down due to lose activity.

Evolution of Physical and Mechanical Properties of Nanostructured Titanium upon Annealing

Nanocrystalline and submicrocrystalline titanium are synthesized using the methods of severe plastic deformation by twisting and equal channel angular pressing with subsequent cold rolling. The microhardness, magnetic susceptibility, and electrical resistivity have maximum values in highly strained titanium. Annealing in the temperature range of 673–1123 K leads to restoration and recrystallization manifested in decreases in the microhardness by a factor of 2, in the magnetic susceptibility by 15%, and in the resistivity by 20%.