Energy Dispersive Electron Research Articles

Mineralogical Features of Ultramafic and Mafic Rocks of Syum-Keu Ophiolite (Polar Urals, Russia): Implications for Petrology and Paleogeodynamics

The Syum-Keu massif is the northernmost ophiolite complex of the Ural mobile belt. It differs from other massifs of the Polar Urals due to the prominent distribution of lherzolites in the upper mantle section. This feature aligns it more closely to some massifs in the southern part of the belt (Kraka). Thus, a comparison of the ultramafic rock compositions in these massifs is highly relevant. Thus, comparing the compositions of ultramafic rocks from these massifs is highly relevant and is one of the primary objectives of this study. Our second objective is to study the microstructural features of ultramafic rocks from the upper mantle, as they can indicate modes of subsolidus processes that played a key role in the formation of this massif. Our study utilizes optical microscopy, assessments of bulk rock composition using X-ray fluorescence and ICP-MS, as well as mineralogical methods, such as scanning electron microscopy with energy dispersive spectroscopy and electron backscattered diffraction, for the microstructural analysis of peridotites. In addition to ultramafic rocks from the upper mantle section, the composition and mineralogy of mafic rocks from the crustal section were studied. The microstructural analysis of ultramafic rocks indicates their two-stage evolution. The first is associated with plastic flow under the upper mantle conditions dominated by the olivine slip along the {0kl}[100] system, while the second reflects formation in the lower crust, with lower-temperature deformation along the {110}[001] slip system. Comparing the mineralogy of the Syum-Keu peridotites to lherzolite massifs in the Southern Urals reveals a significant difference in accessory Cr-spinel composition; the former show elevated iron content (Fe trend), indicating intense crustal metamorphism. Similarly, amphiboles in Syum-Keu ultramafic rocks exhibit a significant crustal (metamorphic) component, while the same minerals in the Kraka massif suggest a mantle (magmatic) origin. Mafic rocks in the Syum-Keu massif also typically display a high degree of metamorphism. The obtained results generally corroborate prior findings on a longer evolution of the upper mantle ultramafic rocks of the Syum-Keu massif compared to those of the Kraka massif. Our results are also consistent with the suprasubduction nature of these ultramafic rocks. Our findings can be utilized in further studies of the microstructure and composition of ophiolites from the Polar Urals to provide a more detailed characterization of the partial melting conditions of the mantle source, the plastic flow of peridotites, and their interaction with melts and fluids.

Synthesis of Cu doped Ba(OH)2 thin film by SILAR method for supercapacitor electrode application

Abstract An economically suitable successive ionic layer adsorption and reaction (SILAR) method has been used to deposit 0.25, 0.50 and 0.75 wt% copper doped barium hydroxide on stainless steel (SS) substrate. X-ray diffraction analysis shows the orthorhombic crystal structure of Cu doped Ba(OH)2 electrode. FTIR analysis reveals the chemical bonds present in the sample. The energy-dispersive x-ray spectroscopy (EDAX) and x-ray photo electron spectroscopy (XPS) measurements have been performed to confirm Cu doping into Ba(OH)2. The electrochemical properties of Cu doped Ba(OH)2 electrode have been analysed by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) techniques. The 0.50 wt% Cu doped barium hydroxide electrode exhibits the highest specific capacitance (Csp) of 356.12 F g−1 (59.55 mF cm−2) at 1 mV s−1 scan rate in 1 M Na2SO4 electrolyte solution. This electrode also shows ~ 85% capacitance retention up to 8000 cycles. A symmetric device has also been fabricated by using two electrodes. This device shows energy and power densities of 1.13 Wh Kg-1 and 279.7 W Kg-1 respectively. This cyclic retention and capacitive behaviour of Cu-doped Ba(OH)2 shows its utility as an energy storage material in the near future.

Biosynthesis, characterization of Ag2O nanoparticles for enhancement of antioxidant and photo degradation activities

Silver oxide (Ag2O) nanoparticles were synthesized via Biosynthesis methods using Croton macrotachyus leaf extract silver sulphate (Ag2SO4) was used as precursors and the extract was used in the reactions as reducing, stabilizing and capping agents which is a very easy and inexpensive synthesis method. Metal oxide nanoparticles characterized using UV–visible, TGA, Fourier transform infrared(FTIR),powder X-ray diffraction(XRD), X-ray photoelectron(XPS), and Scanning Electron Microscopy(SEM) with Energy Dispersive X-Ray(EDX) and Transmission Electron Microscopy(TEM), High Resolution Transmission Electron Microscope(HRTEM), and Selected Area Electron (SAED) which is used for determination of crystalline size, morphology,particle size and oxidation state with composition of elements in the sample. Metal oxide nanoparticles have a significant photo catalytic performance under visible light source confirmed that study supported Ag2O spherical structure, which exhibits enhanced photo catalytic activity and anti-oxidant activities as well as the size of the Ag2O nanoparticles was between 16 nm and 21 nm from the XRD(Scherrer equation),SEM & TEM) imaje software and Photo catalytic activity of Ag2O NPs were assessed against methylene blue (MB) dye degradation under natural sunlight illumination for 60 min. This sustainably photo degraded in direct solar irradiance with remarkable degradation percentage which is greater than 96.35 % and Scavenging activities Ag2O nanoparticles enhanced DDPH scavenging activities was 88 %

Polymeric Schiff base containing phenylhydrazine and 2-thiobarbituric acid: Synthesis, characterization, antibacterial and antifungal studies

Polymeric Schiff base ligand (MFT) derived from 2-hydroxyacetophenone, phenylhydrazine, formaldehyde, and 2-thiobarbituric acid was synthesized via condensation reaction. The synthesized MFT ligand was complexed with the metal acetates of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) to form a polymeric Schiff base-metal complexes. The ligand and its metal polychelates were characterized by Fourier transform infra red (FT-IR), Ultraviolet-visible spectroscopy (UV-vis.), X-ray diffraction (XRD), Proton nuclear magnetic resonance spectroscopy (1H NMR), Thermogravimetric analysis (TGA), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and Electron paramagnetic resonance spectroscopy (EPR). The EPR spectrum of MFT-Cu(II) supported a distorted octahedral or square-planar geometry. The synthesized materials were also screened against bacterial (S. aureaus, S. mutans, B. cereus, S. pyrogenes, S. viridans, S. epidermids, C. xerosis, E. coli, K. pneumonia, P. vulgaris, P. aeruginosa) and fungal strains (A. niger, F. oxysporum, and A. oryzea). Moreover, the MFT-Zn(II) complex have demonstrated good thermal stability, as well as strong antibacterial and antifungal activities compared to the ligand and other metal polychelates.

Biodegradation and mechanical performance of Silane-chitosan-graphene oxide composite coating on AZ31 magnesium alloys for biomedical applications.

Biodegradable magnesium alloy medical implants have attracted considerable interest thanks to their remarkable biocompatibility and mechanical properties. However, the rapid corrosion rate of magnesium alloys in physiological environments presents a major challenge to their practical application. Therefore, this study attempted to design a silane/chitosan /graphene oxide composite coating that reduces the corrosion and enhances the biodegradation of magnesium alloys used in temporary implants. The composite fabrication process adopted a cost-effective spin-coating technique providing a uniform coating of magnesium alloy substrates. Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) results showed a dense and compact silane/chitosan/graphene oxide (Silane/CS/GO) coating on the magnesium coated alloy surface. The mechanical properties of the fabricated silane/chitosan/graphene oxide composite were also investigated by microindentation and scratch tests. The hardness of the magnesium alloy increased from ~268 HV ±13.4 to ~644.13 HV ± 32.2 upon the application of the coating. Moreover, the results showed that the cohesive critical load (LC) of the ternary composite was greater than LC ~ 3.02 ± 0.15 N. In addition, compared to uncoated AZ31 alloys, the friction coefficient and wear volume of the ternary composite decreased from ~0.13 ± 0.02 to ~0.07 ± 0.004 and from ~18 to ~0.04 (106μm3), respectively. Finally, the corrosion of the composite coating was assessed in simulated body fluid (SBF) in vitro at 37 °C. Hydrogen evolution results revealed that graphene oxide seemed to delay the diffusion of corrosive ions into the Mg matrix, while Silane prevented the coupling of GO graphene oxide sheets to the metal surface. Consequently, silane / chitosan /graphene oxide composite coatings could be a very useful material for coating magnesium implant devices. It contributed to reduce the corrosion of the substrate and alleviate the cost and discomfort of implants.

Sustainable building solutions: A comprehensive study on PCPET waste-induced bricks

An exponential increase in plastic production and a substantial rise in plastic waste have forced scholars to seek a sustainable and groundbreaking solution that recycles/reuses plastic waste to minimize its adverse environmental impacts upon disposal. Having been used by various sectors, production of construction material from plastic waste has received more interest. Numerous studies have proven that shredded polyethylene terephthalate (PET) plastic bottles constitute a valuable construction material where plastic waste management/recycling procedures are not effective. The goal of this study lies in factors such as strengthening construction material, reducing carbon emissions in atmosphere and minimizing overall costs. Manufacturing plastic M-sand bricks, and integrating post-consumer PET (PCPET) from single-use plastic water bottles into M-Sand is the main focus of our research. This work used two types of PCPET wastes (washed and unwashed) with different mix proportions of plastic and M-sand, such as 1:1, 1:2 and 2:1 for brick production. The bricks manufactured are tested for durability through compression, water absorption, efflorescence, and dimensional stability, and subsequently, Energy Dispersive X-ray Analysis (EDX) and scanning electron microscopy (SEM) for morphological assessment. By the conducted experiential results, it is evident that the design mixes M3 and M8 guarantee appreciable strength that is 2–1.5 times of other mix designs. The M3 design mix with one part washed PCPET and two parts M-sand has exhibited superior performance, with a compressive strength of 40.29 N/mm², minimal water absorption, and observed homogeneity in SEM. In addition, post-demolition sustainability is addressed by integrating recycled brick aggregate with M-sand, showing optimal results for design mix M8, including a compressive strength of 40.54 N/mm², favorable water absorption, and positive SEM findings. EDX confirmed zero carbon elements in the produced bricks. These findings prove the strength of our research on the sustainable recycling of waste thermoplastics within the circular economy, presenting a promising solution to environmental and economic challenges.

Efficient in situ synthetic routes of the polymeric composite containing clinoptilolite using ultrasonic assistance for sorption of some lanthanides

The ultrasound assistance synthesis strategy of the polymeric composite is based on free radical polymerization of polyallylamine hydrochloride (PAH) cationic polyelectrolyte, with vinyl sulfonic acid (VSA) anionic monomer with microporous crystalline alumino silicate clinoptilolite clay. The P(AH-co-VSA)/clinoptilolite polymeric composite was fully characterized by fourier transform infrared spectroscopy, energy dispersive X-ray, thermogravimetric analysis, and scanning electron microscope. FTIR demonstrated the presence of PAH and VSA, confirming the composition of the prepared composite. It was also used to map the energy-dispersive X-ray to affirm the interdependence of the clinoptilolite into the polymeric matrix. Consequently, the physicochemical characteristics of this copolymer may be adjusted using VSA and PAH suitable combinations. Batch experiments were applied and maximal sorption capacities for studied ions Nd3+, Ce3+, Y3+, Gd3+, and Eu3+ were 36.6, 50.2, 55.9, 57.2, and 57.7 mg/g, respectively. Sorption kinetics and equilibrium isotherm were conducted. Experimental isotherms of studied ions were successfully fit to pseudo-second-order model, langmuir isotherm model. The Dubinin–Radushkevich (D–R) isotherm was found to be applicable and suggesting that, the sorption occurs via a ion exchange reaction. The breakthrough data were measured in a fixed bed column, and variable process factors were examined, including bed depth, flow velocity, and initial metal ion concentration. The experimental work was then focused, for continuous investigations, on Ce3+, Eu3+, and Y3+ to represent light, intermediate, and heavy lanthanides respectively. The overall bed capacity and total metal ion adsorption increased when the flow rate increased. They reduced with rising initial metal ion concentration and bed depth, and reached 22.8, 31.4, and 28.5 mg/g for Ce3+, Eu3+, and Y3+ metal ions, respectively.

Wear behaviour of ceramic coating (Al2O3-40%TiO2) in dry condition for automotive applications

The objective of the current research is to examine the effect of varying loads on the wear behaviour of Al2O3-40%TiO2 ceramic coating deposited by flame spray process and to improve material functionality and increase lifecycle in a cost-effective method. To assess the wear behaviour of the deposition, wear test was conducted using a Pin-on-disk tribometer in accordance with ASTM G99 standards. This test was designed to analyse the wear experienced by the coating in practical applications. Surface morphology was examined using field emission scanning electron microscope (FESEM) and energy dispersion spectroscopy (EDS) technique while 3D-profilometer was utilised to further assess the surface roughness of the deposited coating. It was observed that specific wear rate of the deposition exhibited a decreasing trend with increasing load from 40 to 70 N and sliding velocity from 0.4 to 1 m/s. The lowest coefficient of friction was observed at 70 N and 1 m/s. Wear mechanism analysis revealed different types of wear, including abrasion, metal transfer, and brittle fracture, corresponding to the increasing load and sliding velocity. This study is significant for industries that require high-performance coatings for industries such as automotive, aerospace and manufacturing, where high-performance coatings are needed to withstand heavy loads and friction. The current research findings enhance wear resistance and reduce friction, helps manufacturers to adapt coating for specific operational requirements.

Preparation and characterization of ball milled titanium oxide/multi walled carbon nanotube nanocomposite for supercapacitor applications

In this work, titanium oxide nanoparticles (TiO2 NPs) and TiO2-Multi walled carbon nanotubes (MWCNTs) nanocomposites were prepared using the ball milling technique. The characterization of synthesized nanocomposite was done using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), Raman spectroscopy, and transmission electron microscopy (TEM). Dielectric constant ε1 (ω) and dielectric loss ε2 (ω) were discussed in terms of the dielectric polarization process. The Ac conductivity was increased with increasing MWCNTs amount. The charge carrier transport mechanism was interpreted using the correlated barrier hopping model (CBH). The Impedance spectroscopy showed a non-Debye relaxation in the material. The specific capacitance was increased with increasing MWCNTs concentration. Based on these detailed results, the TiO2-MWCNTs nanocomposites displayed higher specific capacitance than TiO2. In addition, the control of the current density applied onto CV measurements and MWCNTs composition of the electrodes to enhance the capacitance will open up a new strategy for the high-performance supercapacitors.

New three-dimensional flat band candidate materials Pb2As2O7 and Pb2Sn2O7

Energy dispersion of electrons is the most fundamental property of the solid state physics. In models of electrons on a lattice with strong geometric frustration, the band dispersion of electrons can disappear due to the quantum destructive interference of the wavefunction. This is called a flat band, and it is known to be the stage for the emergence of various fascinating physical properties. It is a challenging task to realize this flat band in a real material. 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These findings underscore the importance of investigating the influence of flat bands on electronic energy dispersion, providing a crucial step toward understanding the emergence and characteristics of flat bands in novel materials.

Effect of active powder addition on the mechanical properties of TiCp/manganese steel matrix composites

Abstract Different active powders were incorporated into TiC particle (TiCp) preforms of TiCp/manganese steel matrix composites to enhance the TiC/steel interfacial bonding. The effect of the active powders on bending strength and toughness of the composites was investgated. The composites were fabricated using a squeeze casting infiltration method, with a TiCp volume fraction of 50%. The active powders were mixed powders of Fe and tungsten carbide (WC), Ni and WC, and Ni and Si, respectively. Energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM) were employed to analyze the interfacial microstructure of the composites. The results show that the addition of WCp results in the formation of a (W, Ti)C layer around TiCps, thereby strengthening the interfacial bonding. Conversely, the addition of Fe powder leads to the presence of significant glass-phase material at the interface, which is prone to cracking. Consequently, the composite with active Ni+WC exhibits notably higher bending strength (680.3 MPa) and impact toughness (7.7 J cm−2) compared to the composite with active Fe+WC (574.3 MPa and 2.6 J cm−2), with increases of 18.5% and 196.2%, respectively. Furthermore, the composite with active Ni+Si demonstrates the highest bending strength (886.7 MPa) and good toughness (4.3 J cm−2), which are 54.4% and 65.4% higher than those of the Fe+WC active composite, respectively, and its strength is 30.3% greater than that of the Ni+WC active composite. This improvement is attributed to enhanced wettability between TiCp and the matrix.

Eco-friendly green synthesis of metal oxide nanoparticles prepared from different leaf extracts

Ecologically benign reactants and green synthesis of metal oxide nanoparticles are receiving a lot of attention. This is the most popular way of preparation since it uses chemicals that do not contribute to pollution and promotes the use of non-toxic solvents like water and plant extracts. The goal of the current work is to create ZnO nanoparticles by an environmentally friendly, green process that uses leaf extract from environmentally safe plants like Azadirachta indica (Neem) and Acalypha indica where zinc nitrate serves as the precursor. The crystalline structure of the sample was revealed by X-ray diffraction (XRD) analysis and functional groups were identified using Fourier transmission infrared (FT-IR) spectroscopy. Energy dispersive spectroscopy (EDS) and Field emission scanning electron microscopy (FE-SEM) were used to evaluate the shape, structure and content.

Statistical analysis of lamellar and Widmannstätten structures obtained in Nb-rich γ-TiAl alloy with varied cooling rate and annealing duration

Nb-rich γ-TiAl alloys are of interest for enhanced mechanical properties and oxidation resistance. The influence of cooling rate and annealing duration on microstructural evolution of Nb-rich γ-TiAl alloy (Ti-45Al-8Nb-0.2B) has been meticulously investigated, with emphasis on phase volume fraction, grain size, and lamellar spacing. The alloy was annealed at 1320 °C for 15 min, and then furnace-cooled, oil-quenched or cryogenic quenched, whereas annealing for 2 h and 26 h was followed by water quenching. The post-anneal microstructures were characterized using X-ray diffraction, optical and scanning electron microscopy, along with energy dispersive spectroscopy and electron backscattered diffraction. Across all samples, a fully lamellar microstructure comprising α2 and γ phases has been consistently achieved, along with sporadically observed small β precipitates, and elongated ribbon-like TiB2. Widmannstätten colonies (WC) have been observed with diverse morphologies, most of which exhibited an angle of around 64° to regular lamellae, supporting the theory of {1‾1‾22} twinning in the α-phase for WC formation. The γ phase fraction has decreased with increasing cooling rate and annealing time. Grain size and lamellar spacing have also declined with cooling rate but increased with annealing time. Additionally, the mean size of equiaxed γ grains has enlarged with annealing duration.

Effect of Mg on Plasticity and Microstructure of Al-Mg-Ga-Sn-In Soluble Aluminum Alloy.

Soluble aluminum alloy materials used in underground operational tools are synthesized via a high-temperature smelting process. The microstructure and composition distribution of the alloy were analyzed using X-ray diffraction, metallographic microscopy, and scanning electron microscopy with energy-dispersive X-ray and electron backscatter diffraction techniques. The mechanical properties were evaluated using a universal testing machine and hardness tester, while solubility assessments were conducted in a constant-temperature water bath. This study focuses on the plasticity and dissolution characteristics of Al-Mg-Ga-Sn-In alloys with varying Mg contents. The tensile strength (σb) of the alloy was 181.99 MPa, with an elongation (δ) of 27.49% and cross-sectional shrinkage (φ) of 11.67% at a magnesium content of 3.0 wt.%. Additionally, in the compressive test, the compressive yield strength (σsc) was recorded at 188.32 MPa, while the compression rate (δ) was 27.06% and the section expansion rate (φ) was 138.66%. Furthermore, the alloy demonstrated the ability to dissolve spontaneously in water at 90 °C, exhibiting an average dissolution rate of 1.0 g·h-1cm-2 and a maximum dissolution rate of 3.25 g·h-1cm-2 after 12.0 h. Consequently, this alloy composition not only satisfies the requirements for rapid solubility but also exhibits favorable plasticity, providing a novel reference for the selection of soluble aluminum alloy materials.

Gamma irradiation green synthesis of (polyacrylamide/chitosan/silver nanoparticles) hydrogel nanocomposites and their using as antifungal against Candida albicans and anti-cancer modulator

Silver nanoparticles-loaded hydrogel nanocomposites are exploited for medicinal and pharmaceutical applications. Hydrogel nanocomposites were prepared from acrylamide (Am), chitosan (CS) and AgNO3 utilizing gamma rays. Diverse variables were applied in preparation of silver nanoparticles-laoded hydrogel nanocomposites of (PAm/CS)-AgNPs such as influence of radiation dose and influnece of CS concentration. Diverse techniques were utilized to characterize hydrogel nanocomposites; Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and scanning electron microscopy (SEM). Results confirmed formation of silver nanoparticles-loaded hydrogel nanocomposites of (PAm/CS)-AgNPs. Antifungal activity of (PAm/CS)-AgNPs hydrogel nanocomposites on viability of C. albicans was esitmated. Results displayed the efficient microbial inhibition activity of treatment against C. albicans compared to control. Furthermore, (PAm/CS)-AgNPs hydrogel nanocomposite against cervical cancer HeLa cell line was investigated. Cytotoxicity of (PAm/CS)-AgNPs hydrogel nanocomposites on prior cancer cell line empolyed to prohibition of cell growth assesssed by MTT test. HeLa cancer cell is treated by (PAm/CS)-AgNPs for 48 h exposed a potential apoptotic activity by noticeable up-regulation of p53 gene expression. Moreover, anticancer activity was investigated by down-regulation of platelet-based growth variable receptor beta (PDGFR-β), Bcl2, Cathepsine, and MMP-2 gene expression. antioxidant activity was investigated and results showed antioxidant activity of (PAm/CS) hydrogel and (PAm/CS)-AgNPs hydrogel nanocomposite are 87.8% and 62.9%, respectively.

Plant-mediated synthesis, characterization, and evaluation of a copper oxide/silicon dioxide nanocomposite by an antimicrobial study

Abstract This study presents an innovative, environmentally friendly method for biosynthesizing copper oxide–silica (Cu2O/SiO2) nanocomposites (CSNCs) utilizing an aqueous leaf extract of Callistemon viminalis (C. viminalis). The goal of this work is to fabricate CSNCs using a less hazardous and sustainable synthesis approach. Copper acetate and sodium metasilicate were used as precursors, whereas the C. viminalis green leaf extract was used as the reducing and stabilizing agent. Analysis of the plant extract using Fourier transform infrared spectroscopy indicated the presence of polyphenolic compounds, primarily phenolic acids, which functioned as both reducing and stabilizing agents in the synthesis of CSNCs. A combination of energy dispersive X-ray spectroscopy and scanning electron microscopy was used to study the formation of spherical copper–silica hybrid nanostructures. Powder X-ray diffraction analysis revealed the successful integration of silica with copper(i) oxide (Cu2O) through the presence of distinct Cu2O peaks and a broad amorphous SiO2 peak at 2θ = 22.77°. The thermal stability of the nanocomposites (NCs) was assessed using thermogravimetric analysis and differential thermal analysis under a nitrogen atmosphere. The biogenic NCs also successfully inhibited pathogenic strains of Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans); however, S. aureus was found to be more susceptible to the biocidal activity of the NCs than P. aeruginosa. These findings suggest that this simple, cost-effective, and eco-friendly method for producing biologically active hybrid nanomaterials holds significant promise for future applications in both biological and materials sciences.

Machinability Performance of Single Coated and Multicoated Carbide Tools During Turning Ti6Al4V Alloy

AbstractThis paper presents the machinability performance of uncoated, single-coated, and multicoated carbide tools during turning of Grade 5 (Ti6Al4V) Titanium alloy, which is challenging to machine due to its distinctive material properties. Coated tools with single-coated Titanium Aluminium Nitride (TiAlN) and multi-coated layer of Titanium Aluminium Nitride with Aluminium Chromium Nitride (TiAlN + AlCrN) coated inserts were utilized to assess surface roughness (Ra), tool wear rate (R), and chip morphologies under various cutting conditions using dry machining. Analysis of the used tools revealed that coated tools exhibited improved tool life and surface quality compared to uncoated tools across all cutting conditions. Multi-coated tools of TiAlN + AlCrN demonstrated a tool life increase of up to 15% compared to uncoated and single-coated tools, with surface roughness improvements ranging from 30 to 45% depending on cutting speed. Chip morphology analysis indicated an increase in the chip reduction coefficient with higher cutting speeds for all tool types. Coated tools exhibited the lowest chip-reduction coefficient due to the presence of TiAlN and AlCrN coatings, which control the tool chip contact length. Conversely, uncoated chip morphology resulted in larger chip thickness values compared to coated tools, particularly at cutting speeds above 100 m/min, attributed to poor heat dissipation and chemical reactions at the tool chip interface. Energy dispersive X-ray scanning electron microscopy (SEM/EDXS) analysis of worn uncoated inserts revealed a higher tendency towards Titanium adhesion compared to coated tools. The proposed multi-layer coatings of (TiAlN + AlCrN) used for dry machining proved highly beneficial for achieving economic machining objectives and may reduce the need for lubrication when processing Ti6Al4V alloys.

FIB/SEM serial sectioning as a versatile tool for microstructural analysis

Abstract FIB/SEM tomography is a serial sectioning method in which the cross-sectional area of the sample is stepwise removed with a focused ion beam (FIB) and the exposed cross-sectional area is imaged with a scanning electron microscope (SEM). All imaging techniques of the SEM can be used, which allows the application to a wide range of materials science questions. On the one hand, resolutions of a few nm can be achieved, and on the other hand, volumes with edge lengths of 100 μm and more can be examined. This article gives an overview of the current state of the art and the practical implementation of FIB/ SEM serial sectioning. The special aspects of the integration of energy dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) are also discussed.

A grey relational analysis of the micro arc oxidation process parameters and their effects on Ti-6Al-7Nb coating performance and corrosion resistance for biomedical uses

Abstract In current investigation micro arc oxidation of Ti6Al7Nb alloy was done to improve its surface properties and corrosion resistance. Mixture of Na2SiO3, Na3PO412H2O and KOH is used as electrolyte. MAO treated Ti6Al7Nb specimens were examined using x-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) to examine their morphology and phase composition. It was observed that electrolyte composition is simultaneously included in the growing oxide layer during MAO process. From electrochemical study it was found that corrosion resistance of the Ti6Al7Nb increases during EIS testing in 0.9% NaCl solution. It was found that frequency, duty cycle, current and processing time effect the surface roughness, thickness, hardness and corrosion resistance of coating. Out of above mention parameters frequency and duty cycle has major impact on performance parameters. The objective of current investigation is to find out effects MAO process parameters on coating performance parameters such as coating thickness, hardness, surface roughness and corrosion resistance. At duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min, highest coating thickness 32.96 μm and surface roughness 3.3680 μm was obtained. Process parameters have the influence on pore size, biggest average pore size 3.8519 μm was obtained at duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min. Grey relational analysis is done to determine which process variable has the most influence on performance parameters. From grey relational analysis technique, it was observed that duty cycle 50%, frequency 500 Hz, current 300 mA, and processing time 7.5 min are ideal process parameters for higher coating thickness, hardness, surface roughness and better corrosion resistance. From grey relation analysis it was also found that frequency has most significant impact on performance parameters after that duty cycle, then current and at last processing time.

Comparative analysis of thermoelectric properties in bulk 2H and monolayer MoS2: a first-principles study at high temperatures

The pursuit of high-efficiency heat-to-electricity conversion is one of the indispensable driving forces toward future renewable energy production. The two-dimensional (2D) transition metal dichalcogenide, such as molybdenum disulfide (MoS2), is at the forefront of research due to its outstanding heat propagation features and potential applications as a thermoelectric material. Using the first-principles density functional theory coupled with the semi-classical Boltzmann transport equation within the constant relaxation time approximation, we present the thermoelectric and energy transport in the bulk 2H and monolayer MoS2 material system. In order to advance the underlying physics, we calculate several crucial transport parameters such as electrical conductivity, electronic thermal conductivity, Seebeck coefficient, and power factor as a function of the reduced chemical potential for different doping types and temperatures, in addition to the electron energy dispersion relation of the material system. Our comprehensive study employs the Shankland interpolation algorithm and the rigid band approximation to attain a high degree of accuracy. This thorough investigation reveals the high Seebeck coefficient of 1534 and 1550 μ V/K at 500 K for the bulk 2H and monolayer MoS2, respectively. Furthermore, the ultrahigh power factor values of 9.21 × 1011 and 3.69 × 1011 Wm −1 K −2 s −1 are shown at 800 K in the bulk 2H and monolayer MoS2, respectively. Based on the power factor results, our in-depth analysis demonstrates that the bulk 2H MoS2, when compared to monolayer MoS2, exhibits great potential as a promising semiconducting thermoelectric material for advanced high-performance energy device applications.