Quantum dots (QDs) have sparked great interest due to their unique electronic, optical, and structural properties. In this review, we provide a critical analysis of the latest advances in the synthesis, properties, and applications of QDs. We discuss synthesis techniques, including colloidal and hydrothermal synthesis, and highlight how the underlying principles of these techniques affect the resulting properties of QDs. We then delve into the wide range of applications of QDs, from QDs based color conversion, light-emitting diodes and biomedicine to quantum-based cryptography and spintronics. Finally, we identify the current challenges and future prospects for quantum dot research. By reading this review, readers will gain a deeper understanding of the current state-of-the-art in QDs research and the potential for future development.
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Kushagra Agarwal et al 2023 Mater. Res. Express 10 062001
William Xaveriano Waresindo et al 2023 Mater. Res. Express 10 024003
Hydrogel is being broadly studied due to their tremendous properties, such as swelling behavior and biocompatibility. Numerous review articles have discussed hydrogel polymer types, hydrogel synthesis methods, hydrogel properties, and hydrogel applications. Hydrogel can be synthesized by physical and chemical cross-linking methods. One type of the physical cross-linking method is freeze-thaw (F–T), which works based on the crystallization process of the precursor solution to form a physical cross-link. To date, there has been no review paper which discusses the F–T technique specifically and comprehensively. Most of the previous review articles that exposed the hydrogel synthesis method usually mentioned the F–T process as a small part of the physical cross-linking method. This review attempts to discuss the F–T hydrogel specifically and comprehensively. In more detail, this review covers the basic principles of hydrogel formation in an F–T way, the parameters that influence hydrogel formation, the properties of the hydrogel, and its application in the biomedical field.
Ahmad Y Al-Maharma et al 2020 Mater. Res. Express 7 122001
In the present review, the effect of porosity on the mechanical properties of the fabricated parts, which are additively manufactured by powder bed fusion and filament extrusion-based technologies, are discussed in detail. Usually, additive manufacturing (AM) processes based on these techniques produce the components with a significant amount of pores. The porosity in these parts typically takes two forms: pores with irregular shapes (called keyholes) and uniform (spherical) pores. These pores are present at different locations, such as surface, sub-surface, interior bulk material, between the deposited layers and at filler/matrix interface, which critically affect the corrosion resistance, fatigue strength, stiffness, mechanical strength, and fracture toughness properties, respectively. Therefore, it is essential to study and understand the influence of pores on the mechanical properties of AM fabricated parts. The technologies of AM can be employed in the manufacturing of components with the desired porous structure through the topology optimization process of scaffolds and lattices to improve their toughness under a specific load. The undesirable effect of pores can be eliminated by using defects-free raw materials, optimizing the processing parameters, and implementing suitable post-processing treatment. The current review grants a more comprehensive understanding of the effect of porous defects on mechanical performance and provides a mechanistic basis for reliable applications of additively manufactured components.
Yangang Li et al 2022 Mater. Res. Express 9 122001
Two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted extensive attraction due to their unique properties in novel physical phenomena, such as superconductors, Moiré superlattices, ferromagnetics, Weyl semimetals, which all require the high quality of 2D TMDs. Mechanical exfoliation (ME) as a top-down strategy shows great potential to obtain 2D TMDs with high quality and large scale. This paper reviews the theoretical and experimental details of this method. Subsequently, diverse modified ME methods are introduced. Significantly, the recent progress of the Au-assisted ME method is the highlight. Finally, this review will have an insight into their advantages and limitations, and point out a rational direction for the exfoliation of TMDs with high quality and large size.
Badrut Tamam Ibnu Ali et al 2022 Mater. Res. Express 9 125302
The selection of the solvent during the membrane preparation process significantly affects the characteristics of the resulting membrane. The large number of organic solvents available for dissolving polymers renders this experimental approach ineffective. A computational approach can select a solvent using the solvation energy value approach. In addition, no organic waste is generated from the computational approach, which is a distinct advantage. A computational approach using the DFT/B3LYP/def2-TZVP RIJCOSX method was used to optimize the structure of polyethylene terephthalate (PET). The PET for the experiment was obtained from the utilization of plastic bottle waste. In addition, a review of the thermodynamics, geometry, HOMO-LUMO orbitals, and vibrational frequencies was conducted to validate the PET molecule against the experimental results. A conductor-like polarizable continuum model was used to determine the best solvent for dissolving the PET plastic waste. The results demonstrated that the Fourier Transform Infra-Red and Fourier Transform Raman spectra obtained from computational calculations were not significantly different from the experimental results. Based on a thermodynamic approach, computationally the Gibbs free energy (−724.723), entropy (0.0428), and enthalpy (−724,723 Kjmol−1 ) values of the PET dimer molecule are not much different from the experimental values (−601, 0.042, and −488 Kjmol−1). The computational approach was successful in selecting solvents that can dissolve PET plastic bottle waste. Phenol solvent has the lowest solvation energy value (−101.879 Kjmol−1) and the highest binding energy (2.4 Kjmol−1) than other solvents. Computational and experimental results demonstrated that the phenol solvent was able to dissolve PET plastic bottle waste better than the other solvents.
Jianxin Wu et al 2022 Mater. Res. Express 9 032001
Aluminum and its alloys having lots of advantageous properties are among the most-used metallic materials. So, it is of immense importance to find suitable processes and methods leading to high-quality purified Al melt. In this regard, there are numerous challenges in achieving high purity Al melts, such as its propensity to react with air, oxygen, and water vapor, the presence of a variety of oxide, non-oxide, and solid particle inclusions that lead to the production of pores, cracks, pinholes, and dross, finally adversely influencing the overall quality of the product. The main methods of melt refining are fluxing, floatation, and filtration, but more sophisticated methods have also emerged. The best method for purification can be chosen based on the type of impurities and the desired level of purification. With the industrial development, the need to establish more cost-effective and simpler methods has increased, and in addition, methods should be considered for recycling large volumes of scarp Al parts that contain more impurities. Moreover, achieving high purity melt is also a vital issue for use in specific applications. The present article has been written to discuss the above issues and focus on the study of various methods of aluminum purification.
Muhammad Hafeez et al 2020 Mater. Res. Express 7 025019
Cobalt oxide nanoparticles (Co3O4-Nps) have many applications and now a days the green methods of synthesis of these NPs are preferred over other methods because of associated benefits. In this study, Co3O4-Nps were synthesized by using leaves extract of Populus ciliata (safaida) and cobalt nitrate hexa hydrate as a source of cobalt. The synthesized NPs were analyzed by different techniques such as fourier transform spectroscopy (FTIR), x-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Antibacterial activities of the synthesized Co3O4-Nps were evaluated against gram negative and gram positive bacteria and found active against Escherichia coli (E. coli), Klebseilla pneumonia (K. pneumonia), Bacillus subtillus (B.subtillus) and Bacillus lichenifermia (B. lichenifermia). The activity results were analyzed statistically by one-way ANOVA, with 'Dunnett's Multiple Comparison Test'. The maximum mean activity (21.8 ± 0.7) was found for B. subtilis and minimum mean activity (14.0 ± 0.6) was observed for E. coli.
Xi Huang et al 2020 Mater. Res. Express 7 066517
The oxidation behavior of 316L stainless steel exposed at 400, 600 and 800 °C air for 100, 500 and 1000 h was investigated using different characterization techniques. Weight gain obeys a parabolic law, but the degree of deviation of n index is increasingly larger with the increase of temperature. A double oxide film, including Cr2O3 and Fe2O3 oxide particles in outer and FeCr2O4 oxides in inner, is observed at 400 °C. As regards to samples at 600 °C, a critical exposure period around 100 h exists in the oxidation process, at which a compact oxide film decorated with oxide particles transforms to a loose oxide layer with a pore-structure. In addition, an oxide film containing Fe-rich outer oxide layer and Cr-rich inner oxide layer is observed at 600 °C for 500 and 1000 h. Spallation of oxide scale is observed for all samples at 800 °C regardless of exposure periods, resulting in different oxidation morphologies, and the degree of spallation behavior is getting worse. A double oxide film with the same chemical composition as 600 °C is observed, and the thickness increases over exposure periods.
Veera Prabakaran Elanjeitsenni et al 2022 Mater. Res. Express 9 022001
Thin film sensors are used to monitor environmental conditions by measuring the physical parameters. By using thin film technology, the sensors are capable of conducting precise measurements. Moreover, the measurements are stable and dependable. Furthermore, inexpensive sensor devices can be produced. In this paper, thin film technology for the design and fabrication of sensors that are used in various applications is reviewed. Further, the applications of thin film sensors in the fields of biomedical, energy harvesting, optical, and corrosion applications are also presented. From the review, the future research needs and future perspectives are identified and discussed.
Ruby Garg et al 2020 Mater. Res. Express 7 022001
To meet the energy needs batteries and supercapacitors are evolved as a promising candidate from the class of energy storage devices. The growth in the development of new 2D electrode materials brings a new revolution in energy storage devices with a comprehensive investigation. MXene, a new family of 2D metal carbides, nitrides and carbonitrides due to their attractive electrical and electrochemical properties e.g. hydrophilicity, conductivity, surface area, topological structure have gained huge attention. In this review, we discussed different MXene synthesis routes using different etchants e.g. hydrofluoric acid, ammonium hydrazine, lithium fluoride, and hydrochloric acid, etc showing that fluorine formation is compulsory to etch the aluminum layer from its precursor. Due to the advantage of large interlayer spacing between the MXene layers in MXene, the effect of intercalation on the performance of batteries and supercapacitors using MXene as electrodes by various sized cations are reviewed. Different MXene hybrids as supercapacitor electrodes will also be summarized. Lastly, the conclusion and future scope of MXene to be done in various supercapacitor applications are also presented.
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Miad Ali Siddiq 2024 Mater. Res. Express 11 056304
Yttrium zinc oxide (Zn0.85Y0.15O) nanostructures were stoichiometrically prepared by co-precipitation method. XRD, EDX, XPS, SEM, and TEM spectroscopy were examined to investigate structure, composition, and morphological characteristics. The synthesized nanocomposite exhibited polycrystalline structure with small crystallite size ∼ nm in which the particles appeared in sheets like shape with high atomic density on surface. The optical parameters including energy gap and refractive index were investigated from (T%) and (R%) measurements through wavelength range from 300–900 nm. Al/Y:ZnO/p-Si/Ag Schottky diode was fabricated using thermal evaporating technique and its current–voltage was analyzed using different models. The photodiode showed non-ideal behavior with ideality factor greater than unity and small potential barrier. Under various illuminations, the photodiode has revealed high photosensitivity attributed to trapped charge carriers at the interface. The charge carrier density and built-in voltage were estimated from Mott Schottky (M–S) function suggesting high Schottky diode efficiency.
Vinayak S Hiremath et al 2024 Mater. Res. Express 11 055309
Composite materials, particularly glass fibre-reinforced polymers, or GFRP are being used far more frequently. Airframes have been manufactured utilizing reinforced composites, including struts, frames, and flaps, employing raised epoxy-based co-cure technology. The current research describes a multi-scale approach to fortifying graphene nanoparticles (GNP) and carbon fibre Z-pins in order to strengthen the flat-joggle-flat composite joints with different manufacturing technique. Shear investigation showed that by adding GNPs and putting carbon fibre pins (Z-pins) in a crosswise position (perpendicular to the plane) to the joint's surface, concurrent reinforcement gives rise to greater shear characteristics with quasi-static loads. Specifically, there was a 45.6% improvement in shear resistance when contrasted with unreinforced co-cured FJF joints. The FESEM has been utilized to demonstrate the failure analysis of the specimens, which shows the clear failure mechanism of the FJF joint specimens. The FJF joint with multiscale reinforcement has a very high natural frequency of 685.1 Hz as compared to other configurations, according to the vibration analysis.
Xuanyan Zhao 2024 Mater. Res. Express 11 055901
Photoelectric synapses are attracting intensive attention due to its low power consumption and adaptive learning. However, traditional ferroelectric field effect transistors are not conducive to the integrated application in artificial intelligence systems. Here, we design the all two-dimensional photoelectric synapse device based on WSe2/MoS2/α-In2Se3 ferroelectric van der Waals heterojunction, which has high memory capacity (memory on/off = 105) and synaptic function. In addition, we simulate an artificial neural network to modify the handwritten digit recognition of the National Institute of Standards and Technology. In particular, the recognition rates are 92.4% and 93.6% for electrical synapse and photoelectric synapse, respectively. This work provides an effective strategy for achieving stable integration of neuromorphic computing.
Neil Corda et al 2024 Mater. Res. Express 11 056203
Nanostructured pure and Zn doped CuO thin films were deposited on a glass substrate at 400 °C using the chemical spray pyrolysis method. The fabricated thin films were characterized to study the compositional, structural, morphological, optical and electrical properties. X-ray diffraction spectra show the polycrystalline nature of the sample and confirm the monoclinic phase of copper oxide. Raman analysis further confirms the absence of cuprous oxide phases and impurities. High absorbance in the visible region was observed for the films with bandgap values ranging from 1.7–2.0 eV. A near-band edge emission peak in the red region is recorded in the photoluminescence spectra. Uniformly distributed nanoparticles are observed in SEM images. Hall effect measurements indicate p-type conductivity and 5% Zn doped copper oxide showed the highest conductivity and carrier concentration. The non-linear absorption coefficient (βeff) of the samples was obtained with the help of z-scan method with a Helium-Neon laser under the CW regime. Zn doping results in an increase in nonlinear absorption, supporting the use of Zn:CuO for optoelectronic devices.
Mercy C Ogwuegbu et al 2024 Mater. Res. Express 11 055010
Biosynthesis of metal oxide nanoparticles using plant extract is an inexpensive, simple, rapid, and environmentally friendly approach to obtaining nanoparticles for biological applications. Herein, copper oxide nanoparticles (CuO-NPs) were successfully synthesized using an aqueous extract from Ligustrum lucidum leaves. The structural, optical, and morphological characteristics of the nanoparticles were assessed using x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectrophotometer, transmission and scanning electron microscopy (TEM and SEM), and energy-dispersive x-ray (EDX). Nanocrystalline CuO with an average crystalline size of 22.0 nm and a band gap energy of 1.4 eV were confirmed from the XRD and UV-vis spectrophotometer, respectively. Morphological studies showed spherical nanoparticles, whose particle size estimation (30 ± 5 nm) agrees with the crystalline size deduced from the XRD pattern. A free radical scavenging activity of the CuO nanoparticles, evaluated using the 1, 1-diphenhyl-2-picrylhydrazyl (DPPH) assay, showed that it exhibited high antioxidant activity (IC50: 63.35 μg ml−1) that is concentration dependent. Antifungal evaluation using four different fungal strains (Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, and Trichoderma harzianum) indicated a direct relationship between the potency of the particles and their concentration, with 1 ppm solution exhibiting the highest potency. The green synthesized CuO-NPs using Ligustrum lucidum may be potentially used as an antioxidant and antifungal agent for therapeutic applications.
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Qiaoqiao Lan et al 2024 Mater. Res. Express 11 052001
Bio-based polyurethanes are novel material with potential advantages for sustainable development, and their development play significant roles in promoting sustainability. Curcumin, a natural monomer, possesses high biological activity and features a symmetrical chemical structure with various functional groups such as phenolic hydroxyl, carbonyl and benzene ring. The presence of hydroxyl groups in the structure of curcumin provides essential conditions for its involvement in polyurethane synthesis. This review article provides an overview of the applications of curcumin as a chain extender, crosslinking agent and end-capper in polyurethanes, as well as its effects on the chemical structure, mechanical properties, and chemical stability of polyurethanes. Furthermore, the functional applications of curcumin-based polyurethanes in various fields such as medicine, food packaging, and coatings are discussed. Finally, considering the current research status and inherent properties of curcumin, the future prospects of curcumin-based polyurethanes are contemplated.
Tao Huang et al 2024 Mater. Res. Express 11 032003
As a kind of special energy field assisted plastic forming, electric pulse assisted plastic forming combines multiple physical fields, such as thermal, electrical, magnetic and mechanical effects, has multiple effects on metal. It has a good industrial application prospect in the fields of directional microstructure regulation of materials and preparation of new materials. The flow stress of metal materials can be effectively reduced by electro-pulse assisted forming. The action mechanism of pulse current includes thermodynamics (Joule heating effect) and kinetic (pure electro-plastic effect or athermal effect). Thermodynamically, electric pulses can be used to provide the energy for dislocation migration and atomic diffusion, and aid in microstructure changes such as recrystallization, phase transition and microcrack healing of metals. In terms of dynamics, electric pulse has an effect on the speed and path of dislocation structure evolution. On this basis, a series of theoretical models for accurately predicting the flow stress of materials in electrically assisted forming process were formulated by combining the stress–strain constitutive relationship considering the temperature rise effect and the pure electro-plastic effect. The accuracy of the predicting model is greatly enhanced by the introduction of electrical parameters. The mechanism for electrically assisted forming was further revealed.
Ane Lasa et al 2024 Mater. Res. Express 11 032002
All plasma facing surfaces in a fusion reactor, whether initially pure or an alloy, will rapidly evolve into a mixed material due to plasma-induced erosion, migration and redeposition. Beryllium (Be) erosion from the main chamber, and its transport and deposition on to a tungsten (W) divertor results in the growth of mixed Be-W layers, which can evolve to form beryllides. These Be-W mixed materials exhibit generally less desirable properties than pure tungsten or pure beryllium, such as lower melting points. In order to better understand the parameter space for growth of these alloys, this paper reviews the literature on Be-W mixed material formation experiments—in magnetically confined fusion reactors, in linear plasma test stands, and during thin-film deposition—and on computational modeling of Be-W interactions, as well as briefly assesses the Be-W growth kinetics. We conclude that the following kinetic steps drive the material mixing: adsorption of the implanted/deposited ion on the metal surface; diffusion of the implanted/deposited ion from surface into the bulk, which is accelerated by defects; and loss of deposited material through erosion. Adsorption dominates (or prevents) material mixing in thin-film deposition experiments, whereas diffusion drives material mixing in plasma exposures due to the energetic ion implantation.
Meng Xu et al 2024 Mater. Res. Express 11 032001
Heavy metal ions and organic pollutants cause irreversible damage to water environment, thereby posing significant threats to the well-being of organisms. The techniques of adsorption and photocatalytic degradation offer versatile solutions for addressing water pollution challenges, attributed to their inherent sustainability and adaptability. Silicates exhibit exceptional practicality in the realm of environmental protection owing to their structural integrity and robust chemical/thermal stability during hybridization and application process. Furthermore, the abundance of silicate reserves, coupled with their proven effectiveness, has garnered significant attention in recent years. This detailed review compiles and analyzes the extensive body of literature spanning the past six years (2018–2023), emphasizing the pivotal discoveries associated with employing silicates as water purification materials. This review article provides a comprehensive overview of the structure, classification, and chemical composition of diverse silicates and offers a thorough descriptive analysis of their performance in eliminating pollutants. Additionally, the utilization of diatomite as either precursors or substrates for silicates, along with the exploration of their corresponding purification mechanisms is discussed. The review unequivocally verifies the efficiency of silicates and their composites in the effective elimination of various toxic pollutants. However, the development of novel silicates capable of adapting to diverse environmental conditions to enhance pollution control, remains an urgent necessity.
Arijit Mitra et al 2024 Mater. Res. Express 11 022002
Magnetic materials at the nanometer scale can demonstrate highly tunable properties as a result of their reduced dimensionality. While significant advancements have been made in the production of magnetic oxide nanoparticles over the past decades, maintaining the magnetic and electronic phase stabilities in the nanoscale regime continues to pose a critical challenge. Finite-size effects modify or even eliminate the strongly correlated magnetic and electronic properties through strain effects, altering density and intrinsic electronic correlations. In this review, we examine the influence of nanoparticle size, shape, and composition on magnetic and tunneling magnetoresistance (TMR) properties, using magnetite (Fe3O4) as an example. The magnetic and TMR properties of Fe3O4 nanoparticles are strongly related to their size, shape, and synthesis process. Remarkably, faceted nanoparticles exhibit bulk-like magnetic and TMR properties even at ultra-small size-scale. Moreover, it is crucial to comprehend that TMR can be tailored or enhanced through chemical and/or structural modifications, enabling the creation of 'artificially engineered' magnetic materials for innovative spintronic applications.
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Demir et al
Objective :
To compare the shear bond strength values of current CAD/CAM materials and to evaluate the color changes resulting from immersion in coloring solutions.
Material and Methods:
A total of 160 specimens were prepared from 4 CAD/CAM blocks; lithium disilicate glass ceramic (IPS E.max CAD[EC]), zirconia reinforced lithium silicate ceramic (Vita Suprinity[VS]), polimer infitrated glass ceramic (Vita Enamic[VE]) and hybrid ceramic (GC Cerasmart [GC]). The ceramic specimens were immersed in tea, coffee, cherry juice and distilled water solutions. Color measurements were made. To compare the shear bond strength values, all specimens were bonded to resin cement. Then the specimens were aged with 5000 thermocycling. The failure modes were classified according to stereomicroscope analysis and than scanning electron microscopy images for surface topography were obtained.
Results:
The color change values were significantly greater in coffee compared to other solutions and the highest color change was seen in GC and VE. The highest bond strength values were seen in VS and VE. The shear bond strength values are listed as follows: VS>VE>EC>CS.
Conclusions:
EC and VS can be used, especially in aesthetic restorations, due to their high color stability. Additionally, considering the bond strength values of VS, it appears to be a highly satisfactory material.
Shunmuga Vembu et al
Managing waste materials from mining is of universal interest owing to its massive volume, ecological impacts, health hazards, and disposal challenges despite high operational costs. Advancements advocate for recycling mine waste to sustainably support construction. As the construction sector heavily consumes resources, utilizing mine waste from magnesite mines (MMW) in concrete has gained attention. This experimental study assesses the viability of substituting MMW for natural fine and coarse aggregates in self-compacting concrete (SCC) at intervals of 10% up to 50% by weight. Evaluations were done on fresh (slump flow, T50 slump, V-funnel, J-ring, L-box) and hardened (compressive, splitting tensile, and flexural strength) properties, along with microstructural features, cost, and CO2 emissions. The findings unveil that nearly all mixtures exhibit commendable performance, where mine waste is replaced for fine and coarse aggregates showcasing superior fresh and hardened properties, respectively. Fresh property results reveal the SF1 flow category with VF1 and VF2 viscosity types for the SCC mixtures. Moreover, these SCC mixtures observed substantial strength enhancements of approximately 10% to 15% in compressive, splitting tensile and flexural test results at 28 and 90 days. Microstructural analysis corroborates the observed strength outcomes, indicating a denser concrete matrix. Significant environmental and economic benefits were observed, including a notable 20% reduction in CO2 emissions and 17% cost savings. These findings underscore the potential of integrating MMW into SCC mixtures as a sustainable approach towards construction materials, offering both performance and environmental advantages.
Simooflu Sari et al
AISI 304 stainless steel, which is used in many areas such as chemistry, petrochemistry, storage tanks and food storage, attracts attention in terms of surface hardness and wear resistance, especially when its industrial applications are evaluated. In this study, it was aimed to improve the surface properties of the AISI 304 stainless steel material used as the substrate material. To develop the best surface properties, boriding layers of varying percentages were created. In order to create these layers, B4C, KBF4, SiC and graphite powders were compared using variable ratios. Microhardness and wear tests were performed on the borided samples and microstructure examinations were carried out using optical, SEM, XRD and EDX. It has been determined that the B4C used as boron source should not be less than 20% for the formation of the boriding layer and the double phase FeB/Fe2B. The powder mixture ratio with the highest thickness and hardness value of the boriding layer formed is the powder mixture with 20% B4C, 50% KBF4, 10% SiC and 20% graphite content. It was observed that the layer thickness increased by 63% and the hardness value increased by 11%. It was observed that this powder mixture gave the lowest wear rate compared to the other powder mixtures in the study. The difference between the highest and lowest wear rate is more than 3 times greater.
Peng et al
MAG welding of 07MnMoVR steel was performed at the 2G and 3G positions, and weld formation, microstructure, residual stress, and tensile properties were compared. In this study, welds without defects were obtained at the 2G and 3G positions. The results showed that a larger distortion of the weld at the 3G position was present because of the higher heat input and that the perlage morphology was related to the introduction of the arc weaving process. In addition, the grain size of the filling pass was coarser than that of the cap pass because of the repeated heating process, and the grain sizes of the filling and cap passes increased by approximately 33% for the weld at the 3G position compared with that at the 2G position. In this case, the weld at the 3G position showed a larger residual stress and lower yield and tensile strengths, and the elongation rates and microhardness of the weld at the 3G position were lower than were those of the weld at the 2G position, regardless of the root pass, filling pass, or cap pass.
B. et al
This study seeks to investigate the influence of cement and Arabic gum on the physico-mechanical and microstructural properties of cementitious composites. The influence of varying quantities of Arabic gum on the hydration, fluidity, mechanical performance and microstructure of cement paste was investigated. The influence of Arabic gum on slant shear performance and capillary water absorption was also investigated. The results indicate that the workability of cement was diminished as a result of the ability of Arabic gum to make the cement paste cohesive. It is evident that when the gum Arabic concentration increases from 147 to 174 mm, the resultant slump value for various w/b ratios drops. The adsorption characteristics showed that for a 15 mg/g dosage at 60, 45, 30, and 15 minutes, respectively, 1.43, 1.32, 1.25, and 1.03 mg/g are achieved. For 1% gum Arabic substitution, the highest flexural strength percentage growth is achieved at 38.46%, 23.74%, and 17.29% at 7, 14, and 28 days, respectively. In addition, the inclusion of Arabic gum improved the slant shear strength of cement composite, making it ideal for use as a building repair material with significant application potential. Experiments on the bonding behavior of the produced cementitious composite with the old mortar reveal that the shear bond strength was greatly increased, demonstrating the compatibility between the old and new cement composites. The microstructure and the porosity of the cement matrix also showed denser and compact matrix making them durable to attain better service life.