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This research focuses on the mechanical characterization of FG material graded with Graphene nano-platelets (GPLs) in the transverse direction. Different weight percentages of GPL (0–2 wt. %) were incorporated into epoxy resin for manufacturing the FGM using a simple casting method and the effects were analyzed. This paper aims to enhance the material’s performance, especially focusing on its potential use in biomedical tools. Mechanical tests including assessment on tensile, flexural, impact strength, and microhardness demonstrated substantial improvement in strength and stiffness as compared to other nanocomposite structures. Microstructural analysis using scanning electron microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) analysis which hint at the strong chemical interaction and physical association of GPL nanofiller with the epoxy resin. Thermal analysis was conducted using the Dynamic Mechanical Analysis (DMA) test, which revealed enhanced thermal stability of the FG specimen with a higher glass transition temperature than other carbon nanofillers mixed in epoxy resin. This is advantageous for the FG material to maintain its glassy state, maintaining safety and reliability during high-temperature medical applications. All these findings indicate that the proposed FG-GPL material possesses the necessary mechanical properties, suggesting that customized nanofiller integration could lead to significant advancements in medical procedures, such as in vivo stomach biopsy treatments, drug delivery systems, etc. The material also meets specific anatomical requirements and reduces the risk of malfunction, thereby ensuring patient safety as justified by current experimental investigations. [ABSTRACT FROM AUTHOR]

Abstract India’s cement industry is the second largest in the world, generating 6.9% of the global cement output. Polycarbonate waste ash is a major problem in India and around the globe. Approximately 370,000 tons of scientific waste are generated annually from fitness care facilities in India. Polycarbonate waste helps reduce the environmental burden associated with disposal and decreases the need for new raw materials. The primary variable in this study is the quantity of polycarbonate waste ash (5, 10, 15, 20 and 25% of the weight of cement), partial replacement of cement, water-cement ratio and aggregates. The mechanical properties, such as compressive strength, split tensile strength and flexural test results, of the mixtures with the polycarbonate waste ash were superior at 7, 14 and 28 days compared to those of the control mix. The water absorption rate is less than that of standard concrete. Compared with those of conventional concrete, polycarbonate waste concrete mixtures undergo minimal weight loss under acid curing conditions. Polycarbonate waste is utilized in the construction industry to reduce pollution and improve the economy. This study further simulated the strength characteristics of concrete made with waste polycarbonate ash using least absolute shrinkage and selection operator regression and decision trees. Cement, polycarbonate waste, slump, water absorption, and the ratio of water to cement were the main components that were considered input variables. The suggested decision tree model was successful with unparalleled predictive accuracy across important metrics. Its outstanding predictive ability for split tensile strength (R2 = 0.879403), flexural strength (R2 = 0.91197), and compressive strength (R2 = 0.853683) confirmed that this method was the preferred choice for these strength predictions.

India's cement industry is the second largest in the world, generating 6.9% of the global cement output. Polycarbonate waste ash is a major problem in India and around the globe. Approximately 370,000 tons of scientific waste are generated annually from fitness care facilities in India. Polycarbonate waste helps reduce the environmental burden associated with disposal and decreases the need for new raw materials. The primary variable in this study is the quantity of polycarbonate waste ash (5, 10, 15, 20 and 25% of the weight of cement), partial replacement of cement, water-cement ratio and aggregates. The mechanical properties, such as compressive strength, split tensile strength and flexural test results, of the mixtures with the polycarbonate waste ash were superior at 7, 14 and 28 days compared to those of the control mix. The water absorption rate is less than that of standard concrete. Compared with those of conventional concrete, polycarbonate waste concrete mixtures undergo minimal weight loss under acid curing conditions. Polycarbonate waste is utilized in the construction industry to reduce pollution and improve the economy. This study further simulated the strength characteristics of concrete made with waste polycarbonate ash using least absolute shrinkage and selection operator regression and decision trees. Cement, polycarbonate waste, slump, water absorption, and the ratio of water to cement were the main components that were considered input variables. The suggested decision tree model was successful with unparalleled predictive accuracy across important metrics. Its outstanding predictive ability for split tensile strength (R2 = 0.879403), flexural strength (R2 = 0.91197), and compressive strength (R2 = 0.853683) confirmed that this method was the preferred choice for these strength predictions. [ABSTRACT FROM AUTHOR]

This research involved cold cracking in microalloyed steels, scrutinizing its corrosive impact on physical and mechanical attributes. A comprehensive analysis covers the base material, heat-affected zone, and weld material through microstructural examinations, hardness tests, fracture resistance tests, etc. The heat affected zone exhibits finer grain structures, elevating hardness. The weld region's fracture toughness is compromised by finefeatures, inducing tear ridge, and micro-cracks, collectively diminishing overall toughness. Fractography identifies fracture causes and flaws. Non-destructive dye crack test detects surface very micro crack on the surface, while fracture analysis explores hydrogen's influence. Findings reveal a substantial reduction in CTOD and J-fracture resistance in the weld zone decrease that is attributed to lower weld zone ductility. Weld regions exhibit 35 % lower ductility than the base material, with fractography revealing reduced energy absorption and diminished fracture toughness. The study guides improvements in oil and gas pipeline for safety and durability measures. [ABSTRACT FROM AUTHOR]

This research focuses on developing a mixture design for high)strength geopolymer concrete (HSGPC) complying with the high)strength concrete criteria mentioned in Indian standards. This study focuses on optimizing the content of alkaline activators and binders proportionately. The compressive strength of different proportions of geopolymer mortar was carried out meticulously to determine the optimal proportions of solution-binder (S/B) and sodium silicate)sodium hydroxide (SS/SH) ratios. The aforementioned ratios were optimized using the Technique for Order of Preference by Simi)larity to Ideal Solution (TOPSIS) analysis for further calculation. The mixture proportions for Grades M70, M80, M90, and M100 were determined and verified through experimental validation. To assess the suggested mixture design, a slump test was conducted to quantify the workability, subsequently followed by the evaluation of compressive strength after 24 hours, 7 days, and 28 days. After achieving the desired workability, promising compressive strength was observed as 76, 89, 93, and 104 MPa at 28 days. Finally, the mechanism of strength increment was investigated using various characterization techniques, such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy)dispersive spectroscopy (EDS). The SEM/EDS analysis of the HSGPC proves the dense microstructures of different gel forma)tions. The proposed mixture design procedure falls under the target strength-based method category. It has successfully yielded a strength of 104 MPa for ground-granulated blast-furnace slag (GGBS)-based geopolymer concrete incorporating coarse and fine aggregates. [ABSTRACT FROM AUTHOR]

Finding a relation between microstructure and properties of nanocomposites is challenging for engineers to control properties of polymeric systems by controlling their microstructure or to estimate their microstructure parameters by studying their properties. Since rheological properties can be obtained in stress or strain modes, sweep of temperatures, sweep of frequencies, amplitudes of applied stress or strains sweep and over the time, creating a relationship between rheological properties and microstructure of nanocomposites has a higher practical freedom. Also, rheological properties are highly affected by mixing quality, which is defined microstructure parameters of systems, so rheology can be applied as a tool to estimate the mixing quality of polymeric systems. Therefore, the present study aims to present the structural model for the rheological behavior of nanocomposites were produced under different mixing conditions and establish the relationship between rheological properties and microstructure of these nanocomposites and evaluate the presented structure with Small-angle X-ray scattering data. Thus, elastomeric nanocomposites were produced at different mixing speeds and times. The results indicated at the lower mixing intensity the agglomerates of nanoparticles are first distributed in the rubber system by increasing the time and speed of mixing so at those mixing condition rheological properties decreased. Finally at the higher mixing intensity the aggregates of these particles start to break so the rheological properties increased. Based on the rheological properties, distributing of particles reduces the rheological properties of nanocomposites, while breaking aggregates increases the rheological properties. [ABSTRACT FROM AUTHOR]

Aluminium (Al) based composites enhance the mechanical and wear behavior by heat treatment. The quenching factors like cooling agent, cooling rate and temperature of cooling are expected to influence the hardness, tensile, and wear behavior of the Al MMCs (Metal Matrix Composites). This research shows the outcomes of a sequence of experiments conducted to study the mechanical and wear behavior of the Al6061-Al2O3-MoS2 hybrid composites that are quenched with different quenching agents. Heat treated hybrid composites were subjected to evaluate the hardness, tensile, and wear behavior. The outcomes reveal that the heat treatment significantly enhances the mechanical and wear behavior of hybrid composites. Highest hardness of 138.1 VHN was achieved under the ice quenched samples. The mechanical and wear behavior improved under the ice quenched samples. Voids, particle pullouts and dimples were observed in the tensile fractured surface. Micro pits, delamination layers, ploughing and micro fissures were observed in the wornout surface of the wear test samples.

Any industry that manufactures dies, punches, molds, and machine components from difficult-to-cut materials, such as Inconel, titanium, and other super alloys, largely relies on wire electrical discharge machining (WEDM). In the current study, the effect of the WEDM process parameters on Inconel 600 alloy with untreated zinc and cryogenically treated zinc electrodes was investigated. The controllable parameters included the current (IP), pulse-on time (Ton), and pulse-off time (Toff), whereas the wire diameter, workpiece diameter, dielectric fluid flow rate, wire feed rate, and cable tension were held constant throughout the experiments. The significance of these parameters on the material removal rate (MRR) and surface roughness (Ra) was established using the analysis of the variance. The experimental data acquired using the Taguchi analysis were used to analyze the level of influence of each process parameter on a particular performance characteristic. Their interactions with the pulse-off time were identified as the most influential process parameter on the MRR and Ra in both cases. Furthermore, a microstructural analysis was also performed via scanning electron microscopy (SEM) to examine the recast layer thickness, micropores, cracks, depth of metal, pitching of metal, and electrode droplets over the workpiece surface. In addition, energy-dispersive X-ray spectroscopy (EDS) was also carried out for the quantitative and semi-quantitative analyses of the work surface and electrodes after machining. [ABSTRACT FROM AUTHOR]

This work addresses the feasibility of using waste badminton string fiber in cement and polymer matrices. A badminton racquet, once used, is torn and needs replacement with new strings. These torn strings, once cut from the badminton racquet system, become waste, and these fibers cannot be recycled and remain debris. Hence, this study examines the microstructural and mechanical properties of new fibers and old torn fibers comparatively. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy are used to study the microstructural properties of the fiber. Direct tensile stress is applied to new and old fibers in the universal testing machine varying by one, three, and five strands of the fibers and varying the gauge length to 60, 80, and 100 mm, and the respective energy absorption is calculated. From investigation with a varying number of strands, similar results were observed in both old and new fibers from energy absorption and residual force ratio. From investigation with varying gauge length, the tensile stress of new fibers varies between 648.53 and 749.03 MPa, and that of old fibers is 537.40–625.55 MPa. Young's modulus for new and old fibers is 4870.00 and 4843.50 MPa, respectively. The Weibull statistical approach is used to test the variability of test results. The Weibull modulus varies between 5.27 and 9.17, which shows lower variability. Thus, the tensile stress results obtained for the discarded badminton fibers pave way for incorporating these fibers in cement and polymer matrices to improve the matrix properties. [ABSTRACT FROM AUTHOR]

The combination of various oxide ceramics in layered and functionally graded composites allows for the development of novel materials, including for high-temperature applications. This study demonstrates the possibility of obtaining a thick ZrO2-based coating on a ZrB2–SiC ceramic substrate by the immersion method. For better wettability, the porous ZrB2–SiC substrate is treated with cold plasma without changing the structure and phase composition of the surface. Immersion of the substrate in a ZrO2-based slurry results in the formation of a gradient transition layer due to ZrO2 particle penetration into the pore volume. The interfacial residual microstresses are evaluated experimentally. The residual macrostresses in the samples are calculated by finite element simulation. It is shown that the thermal residual stresses in the ZrB2–SiC substrate are compressive and do not exceed 43 MPa. In the ZrO2 coating and transition layers of the composite, the residual stresses are tensile. Their values increase as they get closer to the outer layer of the ZrO2 coating and reach 1525 MPa. This confirms the conclusions about the presence of tensile residual stresses made in the experimental part of the work when observing crack propagation in the surface layers during indentation. [ABSTRACT FROM AUTHOR]

The present work involves friction stir welding of AZ31B magnesium alloy plates by using copper as tool pin material. The friction stir welding input factors namely tool pin profile, tool rotational speed, tool feed and tool angle were varied to find their influence on the quality of the processed zone. For mechanical and micro structural study of the processed specimens, tensile test, hardness test and microscopy tests were carried out. The Taguchi's experimental combination of L18 mixed orthogonal array has been utilized for conducting experiments. ANOVA was utilized to evaluate the influence of each input factor on the response measures. TOPSIS, the multi-response optimization technique was applied to obtain the optimal setting for getting enhanced results. The experimental results of the optimum set provided a tensile strength of 206.35 MPa, Percentage elongation of 7.4% and Vickers hardness of 68 which are 88.2%, 52.9% and 79% of the corresponding property values of the base material respectively. Microstructural study revealed the refinement of grains in the processed zone. However the enhancement of properties is prevented by the occurrence of defects.

Aluminium (Al) based composites enhance the mechanical and wear behavior by heat treatment. The quenching factors like cooling agent, cooling rate and temperature of cooling are expected to influence the hardness, tensile, and wear behavior of the Al MMCs. This research shows the outcomes of a sequence of experiments to find the wear and mechanical behavior of the Al6061-Al2O3-MoS2 hybrid composites are quenched with different quenching agents. Hardening of the developed hybrid composites was carried out at 510ºC for the time period of 2 hours. Later, the same composite samples were quenched in ice cubes and water separately. Finally, age-hardening was done at 180ºC temperature for 4 hours and then the samples were cooled under room temperature. Heat treated hybrid composites were subjected to evaluate the hardness, tensile, and wear behavior. The outcomes reveal that the heat treatment significantly enhances the wear and mechanical behavior of hybrid composites. High mechanical strength and improved wear characteristics were observed in the hybrid composites which were quenched using ice cubes. The fractured surface of the tensile test samples and the wornout surface of wear test specimens were studied using a SEM analysis.

Any industry that manufactures dies, punches, molds, and machine components from difficult-to-cut materials, such as Inconel, titanium, and other super alloys, largely relies on wire electrical discharge machining (WEDM). In the current study, the effect of the WEDM process parameters on Inconel 600 alloy with untreated zinc and cryogenically treated zinc electrodes was investigated. The controllable parameters included the current (IP), pulse-on time (Ton), and pulse-off time (Toff), whereas the wire diameter, workpiece diameter, dielectric fluid flow rate, wire feed rate, and cable tension were held constant throughout the experiments. The significance of these parameters on the material removal rate (MRR) and surface roughness (Ra) was established using the analysis of the variance. The experimental data acquired using the Taguchi analysis were used to analyze the level of influence of each process parameter on a particular performance characteristic. Their interactions with the pulse-off time were identified as the most influential process parameter on the MRR and Ra in both cases. Furthermore, a microstructural analysis was also performed via scanning electron microscopy (SEM) to examine the recast layer thickness, micropores, cracks, depth of metal, pitching of metal, and electrode droplets over the workpiece surface. In addition, energy-dispersive X-ray spectroscopy (EDS) was also carried out for the quantitative and semi-quantitative analyses of the work surface and electrodes after machining.

This work addresses the feasibility of using waste badminton string fiber in cement and polymer matrices. A badminton racquet, once used, is torn and needs replacement with new strings. These torn strings, once cut from the badminton racquet system, become waste, and these fibers cannot be recycled and remain debris. Hence, this study examines the microstructural and mechanical properties of new fibers and old torn fibers comparatively. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy are used to study the microstructural properties of the fiber. Direct tensile stress is applied to new and old fibers in the universal testing machine varying by one, three, and five strands of the fibers and varying the gauge length to 60, 80, and 100 mm, and the respective energy absorption is calculated. From investigation with a varying number of strands, similar results were observed in both old and new fibers from energy absorption and residual force ratio. From investigation with varying gauge length, the tensile stress of new fibers varies between 648.53 and 749.03 MPa, and that of old fibers is 537.40–625.55 MPa. Young’s modulus for new and old fibers is 4870.00 and 4843.50 MPa, respectively. The Weibull statistical approach is used to test the variability of test results. The Weibull modulus varies between 5.27 and 9.17, which shows lower variability. Thus, the tensile stress results obtained for the discarded badminton fibers pave way for incorporating these fibers in cement and polymer matrices to improve the matrix properties.

The present work deals with assessment of heat treated AISI 1020, a low carbon steel (0.2%-C), on the basis of various destructive testing and microstructural behaviour. The steels samples were heated above the lower critical temperature range, i.e. up to 750°C. The cooling rate of all the samples was different. Mainly, three different cooling medium were taken. They are: water, air and sand. These three heat treated samples were compared with as received sample. Hence the final condition of all the four samples is: as received; normalised; sand cooled; water quenched. After a proper preparation, samples were undergone through various mechanical tests, such as, tension test, shear test, hardness test, and impact test. In addition, the microstructural images, captured by an optical microscope, of all the samples were observed and analysed. The mechanical properties and microstructural attributes obtained in 'heat treated' samples were compared with those results of 'as received' samples. From the present experimental analysis, it was found that heat treatment processes significantly changed/improved the desired properties of the AISI 1020 steel samples. [ABSTRACT FROM AUTHOR]

This communication reports a detail study on manganese (Mn) doping in CaCu3Ti4O12 (CCTO) ceramic (simultaneously doping copper and titanium site) with the help of X-ray Photoelectron Spectroscopy ( XPS), High Resolution - Scanning Electron Microscopy ( HR-SEM), High Resolution- Transmission Electron Microscopy (HR-TEM ) and Raman spectra. The doping of manganese in CCTO ceramic, the dielectric constant was largely decreased due to Mn exist variable oxidation state like Mn+2, Mn+3and Mn+4 due to this reason the grains (GB) and grain boundaries (GBs) slightly behave conducting nature. Raman spectra show the existence of copper oxide and manganese oxide presence in the grain and grain boundary of CaCu2.9Mn0.1Ti3.9Mn0.1O12 (CCMTMO) ceramic. The novelty of Mn-doped CCTO ceramic is that the tangent loss also decreases largely as compared to CCTO ceramic. The dielectric constant and tangent loss of CCMTMO ceramic 375 and 0.3 at 10 Hz temperature, respectively. CCMTMO ceramic is very useful for microelectronic devices. The polycrystalline nature of CCMTMO was to be studied with the help of X-ray diffraction (XRD), HR-SEM, HR-TEM, and Magnetic Property Measurement System (MPMS, Quantum Design). The elemental analysis and oxidation state was confirmed by (Energy Diffraction X-ray) EDX and XPS respectively. The elements were found to be their required stoichiometric and oxidation state. The impedance and modulus spectroscopy also studied.

The combination of various oxide ceramics in layered and functionally graded composites allows for the development of novel materials, including for high-temperature applications. This study demonstrates the possibility of obtaining a thick ZrO2-based coating on a ZrB2–SiC ceramic substrate by the immersion method. For better wettability, the porous ZrB2–SiC substrate is treated with cold plasma without changing the structure and phase composition of the surface. Immersion of the substrate in a ZrO2-based slurry results in the formation of a gradient transition layer due to ZrO2 particle penetration into the pore volume. The interfacial residual microstresses are evaluated experimentally. The residual macrostresses in the samples are calculated by finite element simulation. It is shown that the thermal residual stresses in the ZrB2–SiC substrate are compressive and do not exceed 43 MPa. In the ZrO2 coating and transition layers of the composite, the residual stresses are tensile. Their values increase as they get closer to the outer layer of the ZrO2 coating and reach 1525 MPa. This confirms the conclusions about the presence of tensile residual stresses made in the experimental part of the work when observing crack propagation in the surface layers during indentation.

Bismuth ferrite nanostructure, BiFeO3, (BFO) belonging to perovskite family, was synthesised by a chemical route sintering temperature at 800°C for 6 h. The crystalline phase of the materials was investigated by X-ray diffraction (XRD). The morphology and particle size of the BFO samples were determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis, respectively. The SEM images displayed the bimodal structure with the average grain size was found to be 0.6–3.7 µm. TEM observation confirmed the nanocrystalline nature of the particle having the size in the range of 50 ± 20 nm. We have been studied the charge storage capability and impedance of the BFO using cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The prepared material demonstrates pseudocapacitive nature with a charge transfer resistance of 33 Ω. The synthesised material showed that the optical band gap value (Eg) of BiFeO3 varies between 2.2 eV. [ABSTRACT FROM AUTHOR]

In this paper, a study on whether the use of polymer would affect the engineering properties of marine clay during and after the consolidation stage was carried out. A polymer, polyacrylamide (PAM) was used in this study. Unconfined compressive tests and permeability tests on PAM-treated soil were conducted. The testing results were compared with the results of untreated marine clay. The test results indicated that anionic PAM with 2.0 g/kg by dry weight dosage was the most effective for the sedimentation process of soil slurry with 200% water content. At this dosage, the volume of the slurry can be reduced by 29.3% within the first 2 hours in this study. The unconfined compressive strength of anionic PAM treated marine clay at 14 and 28 days were about 360% and 135% higher than that of untreated marine clay with the same curing time, respectively. However, the permeability reduced by an insignificant amount. A microstructural study was also carried out and the results show that after treatment, more edge-to-face contacts between soil particles were observed, which could be related to the increase in shear strength and the decrease in permeability of the soil. [ABSTRACT FROM AUTHOR]

We have reported the sol-gel synthesis and microstructural, magnetic, magnetocaloric, and critical behaviors of La0.7Ba0.15Sr0.15CoO3 cobaltite. The XRD data refined by Rietveld technology confirms that a sample has a pure perovskite phase with rhombohedral structure. We tested the magnetization curve near the phase transition temperature (TC) from ferromagnetic (FM) to paramagnetic (PM), and made the Arrott diagram which confirmed the existence of the secondary phase transition. The obtained magnetic constants from hysteresis loop offer to the sample the possible use in some interesting technological applications. The M(μ0H, T) isothermal magnetizations have been analyzed to estimate the critical exponents (β, γ, and δ). We found that β exponent is close to that of the mean-field model; however, γ and δ exponents belong to an unconventional model. The reliability of the estimated critical exponents was checked from the magnetic field variations of the magnetic entropy change (− ΔSm) and the relative cooling power (RCP). [ABSTRACT FROM AUTHOR]

Abstract The study advocates the influence of lime (L) and curing period (t) on stabilization of jarosite waste. A number of laboratory strength tests [unconfined compressive (qu) and split tensile strength (qt)] are conducted on artificially cemented jarosite-lime blends (lime = 2.5–10%) with different curing periods (t = 7, 28 and 90 days). The outcomes indicate that both qu and qt increase nonlinearly with the increase in lime content and curing period, which is further justified by microstructural study that illustrates the occurrence of larger agglomeration in particles. In addition to these, a good correlation between qu and qt and L and t was possible by fitting the power function on the outcomes. Furthermore, a unique relationship between qu and qt is also developed, which is independent of L and t (i.e. qt/qu = 0.16).

In the present study, the microstructure and the mechanical properties of GTD-111 nickel-based superalloy were investigated. The alloy was in service as the GE-MS9001 gas turbine 1st stage rotating blade for 105,000 hours at a temperature between 950 to 1000 °C. Two sets of samples were extracted from the airfoil and the root of the blade. Then, they were compared for the microstructural and the mechanical properties changes after the high temperature service. Stress-rupture and Charpy V-notch (CVN) tests were conducted on the samples at 871 °C and two temperatures of 25 and 900 °C, respectively. The microstructure and the fracture surface of the samples were analyzed using a scanning electron microscope (SEM). The results showed degradation in the microstructure and the mechanical properties of the airfoil compared to those of the root due to the long-term service at elevated temperatures. The loss in mechanical properties was due to the coarsening of γ' precipitates and the formation of brittle phases in the grain boundaries. [ABSTRACT FROM AUTHOR]

Supplementary Cementitious Materials (SCMs) have been widely accepted in the concrete industry due to their varied advantages. However, the same reflects little in the case of Cementitious Stabilized Aggregates (CSA). The present work focuses on the potential and practical application of SCMs in CSA based on laboratory-based growth and performance analysis followed by their design aspects and economic advantages. Fly ash and Crushed Granulated Blast Furnace Steel Slag (GBFS) were chosen at 30% and 50% by weight of cement as partial replacement to cementitious material to prepare a cementitious stabilized mix of aggregates. Mechanical and microstructural properties were then assessed through critical tests like Unconfined Compression Strength (UCS), Flexural Strength (FS), Flexural Modulus (FM) and Thermogravimetric Analysis (TGA) over subsequent curing periods. Results from these tests revealed improved performance on including SCMs in significant proportion when compared to cement mix of aggregates. Power-law relationships proved optimal for comprehending strength and stiffness growth in CSA. Mixes with SCMs exhibited higher growth coefficients and growth rates for UCS, FS and FM. TGA data showed higher bound water loss %, indicating increased hydration for SCMs mixes. Composite pavement design revealed a 5 mm increase in the bituminous layer for cement-fly ash mix, while it remained unchanged for cement and cement-GBFS mix. Economic analysis demonstrated SCM cost savings of 6% to 16% in the CSA layer in mixes with SCMs. [Display omitted] • Performance Evaluation of fly ash and GBFS-infused CSA through FM, FS and UCS. • Results showed enhanced mechanical performance, supported by TGA findings. • Simulated power-law relationships in CSA for strength and stiffness behaviour. • Composite pavement design with SCMs-infused CSA showed significant cost savings. [ABSTRACT FROM AUTHOR]

Abstract The present study describes the experimental results regarding the effect of the addition of ceramic whisker, on the microstructural and friction property of plasma sprayed yttria-stabilized zirconia coating sprayed on an Inconel substrate with optimized process parameters. To deposit a bond layer between the ceramic top coat and substrate surface, all samples have coated with the metallic intermediate NiCrAlY bond coat. For the microstructural study, the powders/coatings morphology and wear marks on YSZ coated were investigated by a Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analysis (FE-SEM/EDS). The mass loss, wear resistance and coefficient of friction of the YSZ top coat against Alumina Ball were tested with a ball-on-disc wear testing at loads of 7,10 and 13 N. The results showed that reinforced coating gives a higher wear resistance compared to the conventional coating without changing the friction coefficient. The improvement in wear resistance of the ceramic whisker reinforced coatings could be mainly due to the interlocking interface between splats and decrease of intralamellar cracks in the top coat. The wear mechanisms of reinforced and unreinforced TBC were discussed in terms of exfoliation and degradation wear mechanisms. Highlights • Microstructure, wear performance and wear mechanisms of whisker reinforced TBC under sliding against Alumina ball were studied for the first time. • Reinforced coating gives a higher wear resistance compared to the conventional coating. • The wear mechanisms of reinforced and unreinforced TBC were discussed in terms of exfoliation and degradation wear mechanisms. [ABSTRACT FROM AUTHOR]

Estimation of finite strain and microstructural analysis of deformed rocks are keys to better understanding deformational processes and related structures in a variety of scales started from microscopic fabric development to regional-scale structures. In the present work, we carried out the quantitative calculation of strain using the Rf/φ and Fry methods for quartz, feldspar and mafic grains (e.g. biotite and hornblende) from twenty two collected samples for granitic gneiss, amphibolite and hornblende schist samples from the Um Junud area situated in south Eastern Desert of Egypt. Forty four thin sections were prepared and measured by using finite strain methods. The strain data indicate high to moderate ranges of deformation of the amphibolite to granitic rocks. The axial ratios in the XZ section range from 1.74 to 4.37 and 1.50 to 4.46 for the Rf/φ and the Fry methods respectively. The finite strain direction for the long axes displays clustering along N to WNW trend, and shallow WNW plunging in the majority of the studied samples. The short axes are found to be subvertical associated with a subhorizontal foliation. It is concluded that finite strain is of the same order of magnitude for various lithologic units outcropping in the area, and that contacts were formed under semi-brittle to semi-ductile deformation conditions. Thus, the finite strain accumulated during superimposed deformation on a previously nappe structure assemblage, which pointed out that these contacts were created during the accumulation of finite strain. This result is inconsistent with the generally believed that nappe creation in orogens carried out by simple shear deformation. [ABSTRACT FROM AUTHOR]

Increasing the strain rate at superplastic forming is a challenging technical and economic task of aluminum forming manufacturing. New aluminum sheets exhibiting high strain rate superplasticity at strain rates above 0.01 s−1 are required. This study describes the microstructure and the superplasticity properties of a new high-strength Al-Zn-Mg-based alloy processed by a simple thermomechanical treatment including hot and cold rolling. The new alloy contains Ni to form Al3Ni coarse particles and minor additions of Zr (0.19 wt.%) and Sc (0.06 wt.%) to form nanoprecipitates of the L12-Al3 (Sc,Zr) phase. The design of chemical and phase compositions of the alloy provides superplasticity with an elongation of 600–800% in a strain rate range of 0.01 to 0.6/s and residual cavitation less than 2%. A mean elongation-to-failure of 400% is observed at an extremely high constant strain rate of 1 s−1. The strain-induced evolution of the grain and dislocation structures as well as the L12 precipitates at superplastic deformation is studied. The dynamic recrystallization at superplastic deformation is confirmed. The superplastic flow behavior of the proposed alloy is modeled via a mathematical Arrhenius-type constitutive model and an artificial neural network model. Both models exhibit good predictability at low and high strain rates of superplastic deformation.

Insulators comprise only 5% of the capital cost of transmission lines; they are accountable for 70% of line interruptions and 50% of maintenance costs of transmission lines. Major transmission lines situated in different parts of the world were mostly all constructed 30 years ago. These lines have either completed or are approaching the active life at 30 years. It is not possible to replace all insulators at a time in any utility. From a standpoint of consistency, it is quite important to locate insulators that require replacement prior to the occurrence of failure. Recalling these issues, a replacement strategy was modeled on insulator samples, operated at 154 kV, mechanical and electrical rating (M+E) 25,000 lbs and within the 10–50 years (Y) age group, collected in bulk for laboratory evaluation, based on the probability of mechanical failure (P(F)) of insulators. For conducting these studies, tensile load test such as combined electrical and mechanical failing load test was performed on selected 30 new and aged porcelain insulator samples from bulk to access recent condition. It was observed that insulators under service for 50 years manifested a decrease of 89.3% in quality factor (K), as compared to insulators within 10 years of service. A micro-structural study was carried out by using an optical microscope (OM) and a scanning electron microscope (SEM) for the further confirmation of previous evaluations. P(F) was derived by implementing Weibull distribution on the experimental observations. It was observed that insulators with an age of 50 years depicted a 2.7% increase in P(F), as compared to insulators with an age of 10 years. This article discussed a strategy for accessing the recent condition of new, aged bulk samples and the criteria of the replacement of the insulator string based on P(F).

In this study, nanocrystalline ZnO-SnO mixed metal oxide powder was prepared by co-precipitation using Zn(CHCOO)∙2HO and SnCl∙5HO as precursor materials. The powder was characterized by X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. Williamson-Hall method was used to evaluate the micro structural parameters of ZnO-SnO such as crystallite sizes and lattice strain. The photoluminescence property of the sample was studied at different temperatures (10-300 K). Results showed that the emission intensity decreases with temperature increasing. The photocatalytic activity at the gas-solid interface was assessed by monitoring the degradation of nitrogen oxides, a major atmospheric pollutant. The results show that the nanocrystalline ZnO-SnO mixed metal oxide powder exhibits higher and more stable photocatalytic activity against photocorrosion than ZnO alone. Graphical abstract: [ABSTRACT FROM AUTHOR]

Coating of steel surfaces with titanium films has been studied with the objective to protect them against corrosion, and to create an intermediate film for CVD diamond and TiN film deposition. In this work, the nucleation, growth mechanisms and microstructural formation of the titanium films deposited on 304 stainless steel (304 SS) substrate are presented and discussed. The titanium films of variable thickness were obtained by vapour phase deposition produced by electron beam. The surfaces of these samples were observed by scanning electron microscopy. The cross sections of these samples were observed by using an atomic force microscope. The Ti film-304 SS interfaces were analyzed by X-ray diffraction. The results showed that titanium films have a columnar growth. The Ti film-304 SS interface had a residual compression stress at room temperature due to the inter-diffusion process.

Friction welding is widely used as a mass-production method in various industries. Friction welding of tube-to-tube plate using an external tool (FWTPET) is an innovative friction welding process and has potential applications in aerospace, railways, automotive, and marine industries. FWTPET is capable of welding tube-to-tube plate of similar and dissimilar metals and is capable of producing good-quality leak-proof weld joints. In this work, FWTPET welds have been produced with six different tube projections. Tool steel has been used to join the FWTPET process. After the completion of welding, macrostructural and microstructural studies have been conducted and it reveals the weld configuration that is capable of generating defect-free welds. Further, hardness and pull strength of welds obtained with six different tube projections have been studied. When compared to other weld conditions, 1 mm projection has resulted in better strength. The weld strength and average weld interface hardness with 1 mm projection are 84.72 MPa and 70.58 Hv respectively. The sufficient heat generation has been occurred at optimum projection in FWTPET process. [ABSTRACT FROM AUTHOR]

Highlights: [•] The PLA–HA film shows well scattered dispersion of HA domains in between the PLA chains. [•] Increased surface roughness was observed with the presence of protuberance with HA domain. [•] Incorporation of humic acid in the PLA film slightly escalated the thermal stability. [•] The film shows reduction in the degree of crystallinity. [ABSTRACT FROM AUTHOR]

Carbon-rich amorphous boron carbide (B x C) coatings were annealed at 400°C, 700°C, 1000°C and 1200°C for 2 h in air atmosphere. The microstructure and composition of the as-deposited and annealed coatings were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-Raman spectroscopy and energy dispersive X-ray spectroscopy (EDS). All of the post-anneal characterizations demonstrated the ability of carbon-rich B x C coatings to protect the graphite substrate against oxidation. Different oxidation modes of the coatings were found at low temperature (400°C), moderate temperature (700°C) and high temperature (1000°C and 1200°C). Finally, the feasibility of the application of carbon-rich BxC instead of pyrolytic carbon (PyC) as a fiber/matrix interlayer in ceramics-matrix composites (CMCs) is discussed here. [ABSTRACT FROM AUTHOR]

Polyphase deformation and metamorphism of pelitic schists of Chorbaoli Formation of Sausar Group in and around Ramtek area, Nagpur district, Maharashtra, India has led to the development of garnet and sataurolite porphyroblasts in a predominantly quartz-mica matrix. Microstructural study of oriented thin sections of these rocks shows that garnet and staurolite have different growth histories and these porphyroblasts share a complex relationship with the matrix. Garnet shows at least two phases of growth — first intertectonic between D1 and D2 (pre-D2 phase) and then syn-tectonic to post-tectonic with respect to D2 deformation. Growth of later phase of garnet on the earlier (pre-D2) garnet grains has led to the discordance of quartz inclusion trails between core and rim portion of the same garnet grain. Staurolite develops only syn-D2 and shows close association with garnet of the later phase. The peak metamorphic temperature thus coincided with D2 deformation, which developed the dominant crenulation schistosity (S2), regionally persistent in the terrain. The metamorphic grade reached up to middle amphibolite facies in the study area, which is higher than the adjoining southern parts of Sausar Fold Belt. [ABSTRACT FROM AUTHOR]

• multiferroic (1- x)BSZT +x NCZGF composites were synthesized using a standard solid state reaction technique. • Rietveld refinement confirmed the crystal structure with the P 4 mm + F d 3 ¯ m space groups of (1- x)BSZT +x NCZGF. • The experimental values of M s and ε′ of the composites are consistent with different theoretical models. • Minimum loss was observed in the magnetic and dielectric studies of the present research. • The maximum ME (~194 mV cm−1 Oe−1) response in 0.9BSZT+ 0.1NCZGF composite was observed. The magnetoelectric voltage coefficient at room-temperature is realized in various (1- x)BSZT+ x NCZGF composites by studying refined crystal structures, surface morphology, magnetic, electric and ferroeletric properties. The ferroelectric (BSZT) and ferrite (NCZGF) phases of the composites are prepared using standard solid-state reaction technique. Rietveld refinement confirmed that the BSZT phase forms perovskite structure with P 4 mm space group and NCZGF phase forms spinel structure with F d 3 ¯ m space group. From FESEM surface morphology it was observed that the average grain diameter ranges 0.5–2.21 µm. EDX analysis confirms the formation of respective phases and composites. Initial permeability increases from 55 to 130 with increasing NCZGF content which is consistent with the value calculated theoretically using different models. The saturation magnetization also increases from 12 to 37 emu/g with increasing NCZGF content, consistent with the calculated value using law of approach to saturation technique. The dielectric constant of the composites is found to decrease with increasing NCZGF content which is in line with the Maxwell-Garnett, Bruggeman, Looyenga and Lichteneker theoretical approximations. Frequency dependence of the dielectric constant exhibits dispersion, which can be modeled using a modified Debye function that considers the probability of several ions contributing to the relaxation. The ac conductivity follows the Jonscher's power law, and the conduction mechanism is attributed to the small polaron hopping. Complex impedance is evaluated using the Cole-Cole plot ensures the dominance of both grain and grain boundary resistances. The P-E hysteresis loops ensure the typical ferroelectric nature at room-temperature for x ≤ 0.2. The simultaneous M-H and P-E hysteresis loops confirm the magnetoelectric coupling between ferrite and ferroelectric phases. Furthermore, the maximum magnetoelectric voltage coefficient for 0.9BSZT+ 0.1NCZGF composite is found to be ~194 mV cm−1 Oe−1 that can be used in multifunctional devices. [ABSTRACT FROM AUTHOR]

• Sugarcane bagasse ash (SCBA) was produced by autogenous combustion. • SCBA samples with three different particle sizes were assessed by their pozzolanic reactivity. • The lower the particle size of SCBA, the higher the reactivity. • The improved reactivity lead to significant higher compressive strengths in pastes. Studies on reactivity of sugarcane bagasse ash (SCBA), obtained by an autogenous combustion process, with low loss on ignition and three different particle sizes were carried out (SCBA-1, SCBA-2 and SCBA-3). The ashes were characterized by their particle size distribution, chemical composition, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM). The ash with lowest particle size was SCBA-3, followed by SCBA-2, which both were finer than SCBA-1. Calcium hydroxide/SCBA blends were assessed by means of loss of electrical conductivity (Lc), TGA and FESEM. Portland cement/SCBA pastes were analyzed through isothermal calorimetry, TGA, FESEM and compressive strength. Results showed that SCBA with lowest particle size (SCBA-3) presented highest reactivity, which resulted in statically significant better compressive strength than that of control paste (with only Portland cement) after 28 days of curing. The improvement on compressive strength by employing SCBA-3 respect to control and SCBA-1 were 17.9 and 14.1%, respectively, after 180 days of curing. [ABSTRACT FROM AUTHOR]

The role of different deformation mechanisms and the contributing factors behind them needs to be clearly defined to develop materials exhibiting high strain rate superplasticity. It is still not fully understood to what extent the deformation conditions and microstructural parameters affect the mechanisms of superplastic deformation. A novel Al–3.9Zn–4.1Mg–0.8Cu–2.8Ni–0.25Zr alloy is employed to determine what effects the testing conditions, elemental and phase composition and evolution of grain and sub-grain structure make towards deformation mechanisms. To analyze the deformation behavior and microstructure evolution, uniaxial tensile tests are performed following two deformation regimes with the different constant strain rates and temperatures: (1) 2 × 10-3 s-1, 480°С and (2) 2 × 10-2 s-1, 440°С. The elongation to failure exceeds 650% and the strain rate sensitivity coefficient m is near 0.5 at both deformation regimes. Electron microscopy and focused ion beam techniques are employed to analyze mechanisms associated with grain boundary sliding and intragranular strain by using the samples in a stable flow. Surface grids indicated that superplastic flow is accompanied by the formation of striated regions on the surface, whereas grain boundary sliding involves grain neighbor switching and grain rotation. Intragranular deformation with increased dislocation density and dynamic recrystallization are also observed. Weaker intergranular and intense intragranular deformation are revealed at high strain rate deformation regime. Solute effect and the presence of two types of secondary phases, nanoprecipitates of L1 2 -Al 3 Zr and micron-sized eutectic Al 3 Ni, are discussed in comparison to conventional AA7475 alloy in different aspects of grain growth, dynamic recrystallization and strain-rate sensitivity. [ABSTRACT FROM AUTHOR]