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The aim of this study was to evaluate the cyclic fatigue resistance of Dia-X, WaveOne Gold and One Curve files in a water bath at intracanal temperature (35°C). Thirty-nine instruments Dia-X, WaveOne Gold, and One Curve systems (n = 13) were tested in an artificial canal with a curvature angle of 60° and a radius of 3 mm. A water bath setup at a temperature of 35°C was used to simulate the intracanal temperature and time to fracture (TTF) as seconds was recorded. The mean data were analyzed statistically using one-way ANOVA, and post hoc Tukey test (p =.05). The fractured surface of the instruments was examined with scanning electron microscopy (SEM) and chemical composition of the instruments were investigated with energy dispersive X-ray spectroscopy (EDS). Statistically significant differences were detected in TTF values of all the systems as follows: One Curve > WaveOne Gold > Dia-X (p

High-current pulsed electron-beam (HCPEB) surface modification of Al-Co-Cr-Fe-Ni high-entropy alloy (wt. %) Al—15.64; Co—7.78; Cr—8.87; Fe—22.31; Ni—44.57, fabricated via wire-arc additive manufacturing was studied. The initial condition of the sample is characterized by a highly inhomogeneous distribution of the chemical elements that form the alloy. The alloy samples were irradiated with the different electron beam energy densities of 10, 20 and 30 J/cm2. The surface structure was then analyzed in relation to an energy deposition mode. The study has established that HCPEB induces a high-speed crystallization structure with cells varying in size from 100 to 200 nm. There are nano-dimensional (15–30 nm) second-phase inclusions enriched with atoms of Cr and Fe along the grain boundaries. The most liquating elements are Cr and Al. Electron beam surface modification of the high-entropy alloy induces its homogenization. The study has highlighted that the mode of 20 J/cm2, 50 µs, 3 pulses, 0.3 s−1 results in the formation of a surface layer with the most homogenously distributed chemical elements.

The application of thin monolayers helps to increase the endurance of a cutting tool during the drilling process. One such trendy coating is TiAlN, which guarantees high wear resistance and helps to “smooth out” surface defects. For this reason, a new type of weak TiAlN microlayer with a new composition has been developed and applied using the HIPIMs magnetron sputtering method. The aim of this study was to analyze surface-applied micro coatings, including chemical composition (EDX) and microstructure in the area of the coatings. Microstructural characterization and visualization of the surface structures of the TiAlN layer were performed using atomic force microscopy. To study the surface layer of the coatings, metallographic cross-sectional samples were prepared and monitored using light and electron microscopy methods. The microhardness of the test layer was also determined. Analyses have shown that a 2-to-4-micron thick monolayer has a microhardness of about 2500 HV, which can help increase the life of cutting tools.

Innovative textile materials can be obtained by depositing different coatings. To improve the thermal properties of textiles, aluminum and zirconium (IV) oxides were deposited on the Nomex® fabric, basalt fabric, and cotton fabric with flame-retardant finishing using the magnetron sputtering method. An assessment of coating quality was conducted. Evenly coated fabric ensures that there are no places on the sample surface where the values of thermal parameters such as resistance to contact heat and radiant heat deviate significantly from the specified ones. Energy-dispersive spectroscopy was used for the analysis of modified fabric surfaces. Non-contact digital color imaging system DigiEye was also used. The criterion allowing one to compare surfaces and find which surface is more evenly coated was proposed. The best fabrics from the point of view of coating quality were basalt and cotton fabrics coated with aluminum as well as basalt fabric coated with zirconia. The probability of occurrence of places on the indicated sample surfaces where the values of thermal parameters (i.e., resistance to contact heat and radiant heat) deviated significantly from the specified ones was smaller for Nomex® and cotton fabrics coated with zirconia and Nomex® fabric coated with aluminum.

This study investigated the interface morphology, microstructure composition and connection strength of 7A52 aluminum alloy-Al2O3 ceramic brazed joints under heat treatment conditions. Alumina ceramics were first treated with electroless nickel plating, followed by vacuum heat treatment at different temperatures. Then an Al-Si-Mg intermediate layer was placed between the treated alumina ceramic and 7A52 aluminum alloy for brazing under the conditions of welding temperature 590, holding time 1h, pressure 2 MPa. Results showed that when heat treatment was performed at 350°C and below, the nickel-plated metal had an amorphous structure, and when performed at 400°C, the nickel-plated layer had a crystalline structure and the brittle phase Ni3P was precipitated. When the heat treatment temperature was 350°C, the joint shear strength reached the maximum, which was 68.7 MPa.

Herein the deposition and characterization of CuO films with various doping concentrations of boron through the application of the SILAR method are performed. Structural, morphological, and optical properties of the films are determined by SEM with EDS, XRD, and UV/Vis spectroscopy. EDS analysis proved the boron contributions in the films. SEM images showed that boron-doping has a decreasing effect on particle size i.e. the thickness and the length of the nanostructures decreased from 45 to 30 and from 224 to 150 nm, respectively. XRD analyses demonstrated that the crystallite size of the films increased from 12.9 to 15.9 nm with increasing boron concentration which is evidence for increased crystallinity. UV/Vis spectroscopy analysis demonstrated that band gap energy value effectively decreased by boron doping.

Sprayed fiber-reinforced concrete is used in construction for the execution and repair of reinforced concrete elements. It is believed that the addition of steel fibers is most effective, due to their parameters and low costs. Some researchers, however, suggest that the addition of steel fibers can contribute to the initiation of corrosion of the main reinforcement. In consideration of the differences of opinion on the corrosion resistance of sprayed fiber-reinforced concrete, it has become necessary to analyze this issue. The article presents comparative studies of corrosion assessments of the main reinforcement in specimens made of ordinary concrete and concrete with steel fibers. The tests were performed using a semi non-destructive galvanostatic pulse method, which allows location of the areas of corrosion and estimation of the reinforcement corrosion activity. In order to initiate the corrosion processes the specimens were subjected to freezing cycles in NaCl solution. In addition, the shrinkage and compressive strength of specimens were measured, and the observation of specimen structure under a scanning microscope was performed. It was found that galvanostatic pulse method allowed estimation of the reinforcement corrosion progress. The corrosion of the main reinforcement in steel fiber reinforced concrete specimens was less advanced than in the specimens without fibers.

Visual appearance—colour and texture variation—of weathering steel was compared by testing weathering steel samples in aggressive and non-aggressive conditions, and cyclical changes of ambient temperature. This paper introduces a new method for determining visual appearance of weather-resistant steel in different environmental conditions. Weathering steel samples were tested in H2O, 3% NaCl and 3% Na2SO4 solutions under ambient temperature changing from +20°C to −20°C per day. The structure of steel surface viewed under optical microscope revealed corrosion products in all steel samples. X-ray diffraction analysis of corrosion products revealed the presence of oxy-hydroxides, such as lepidocrocite (ɣ-FeO (OH)), goethite (α-FeO(OH)) and magnetite (Fe3O4) in different environment. Optical microscopy images of corroded surfaces had different visual appearance and orange, yellow, sandy, black or anthracite colours, which indicate that the corrosion products primarily contain lepidocrocite (ɣ-FeO(OH)), goethite (α-FeO(OH)) and magnetite (Fe3O4). EDS analysis revealed that the rust of samples kept in 3% NaCl solution had the highest amount of iron ions.

Electroless low-phosphorus Ni–P coating was deposited on a wrought ZE10 magnesium alloy including an advanced pre-treatment of the material surface before deposition. Uniform Ni–P coating with an average thickness of 10 µm was formed by 95.6 wt % Ni and 4.4 wt % P. The content of Ni and P was homogeneous in the entire cross-section of the coating. Applying the Ni–P coating to the magnesium substrate, the surface microhardness increased from 60 ± 4 HV 0.025 to 690 ± 30 HV 0.025. Using the scratch test, it was determined that deposited Ni–P coating exhibits a high degree of adhesion to the magnesium substrate. Electrochemical corrosion properties of Ni–P coating were analyzed using the polarization tests in 0.1 M NaCl, while the deposited Ni–P coating showed an improvement of the corrosion resistance when compared to the ZE10 magnesium alloy. Using the scanning electron microscopy analysis, it was determined that the fine morphology of the deposited Ni–P coating did not contain visible microcavities. The absence of macrodefects due to the adequate pre-treatment before coating was reflected on the mechanism of the coated ZE10 degradation in a 0.1 M NaCl solution.

The aim of the study is to achieve fine microstructure of AZ91, due to the optimized heat treatment processes, which can be easily coated with a normal conversion process as phosphating. Determination of the influence of the AZ91 microstructure, mainly precipitates which are created using different cooling media during the heat treatment and definition of the best heat treatment process parameters are the main experimental sections of the work. The structure of the samples heat treated under different conditions was subsequently compared with the structure of the as cast state of AZ91. The morphology of the conversion coating was studied by scanning electron microscopy (SEM) and amount of individual elements in the deposited coating was determined by EDS analysis.

A peculiar type of edge discoloration defect on the surface of some galvanized fuel tank was observed, causing significant appearance problems. In the present study, the surface defect was characterized by visual inspection, optical microscopy, scanning electron microscopy and energy dispersive spectroscopic analysis to understand the source and mechanism of the defect. In the visual inspection, these peculiar surface appearances were observed in fuel tank at three distinct locations. The SEM examination exhibited two distinct regions on the surface apart from the normal galvanized surface: (1) galvannealed, (2) mixture of galvanized and galvannealed texture. The energy dispersive spectroscopic analysis of galvannealed region indicated enrichment of Zn and Al whereas in the region of galvanized majorly Zn was observed. Surface texture of galvannealed region showed majorly zeta crystals along with skin pass marks; whereas no such zeta crystals were observed in case of galvanized regions. Based on the preliminary results, the following hypothesis was made: Coil processed during galvanizing to galvannealing transition. Thickness and width changed to wider and thicker section, which resulted into lower line speed. Due to the lower Al content, lower speed and thicker section combination resulted in formation of partial GA in the coil owing to the internal heat content of the coil. This paper presents the results of the investigation.

The study was carried out in order to estimate reliability of EDS analysis for identification of various naturaland anthropogenic metal-bearing phases in polished and rough particle samples of stream sediments. For thispurpose, the accuracy and precision of EDS analysis were assessed. Results of the precision measurements showedthat the overall relative standard deviation of EDS measurements was 8 % for polished samples and 24 % for roughparticle samples and was within acceptable limits for most of major elements and some of the elements present inminor or trace contents in the analysed metal-bearing phases. The random analytical fluctuations were considerednegligible and phase compositions could be determined with sufficient reliability in individual grains of each phase.The overall average relative error for all elements amounted to about 12 %, which was within acceptable limits foraccuracy in EDS analysis of polished samples. Chemical formulae and identification of mineral species of metalbearingphases were thus calculated from atomic ratios between constituent elements with sufficient accuracy. Acomparison between EDS measurements in polished and rough particle samples using the Welch’s t-test showedthat about 38 % of studied metal-bearing phases could be identified with sufficient reliability by EDS analysis ofrough particle samples. The results of this study demonstrated that elemental composition of metal-bearing phasesin polished and rough particle samples was mostly determined with sufficient precision and accuracy using EDSanalyses.

With the intention of producing a metal composite consisting of Ag nanoparticles embedded in patterned polystyrene, silver triphenylphosphine nitrate, Ag(PPh3)3NO3, was chosen as a source of Ag metal as it is soluble in toluene to form a blend with polystyrene, a well-known negative tone e-beam resist. At a constant e-beam dosage of 150 ?C cm-2, the patterns were produced at 5, 10, and 30 keV beam energies while varying the dwell time at a location (pixel) and the number of passes. The presence of Ag in the patterned regions was confirmed by the EDS analysis. TEM showed the formation of small Ag nanoparticles in the embedded matrix of the polymer. The reduction of Ag precursor following exposure to the e beam was monitored by XPS. UV-vis absorption studies showed a broad peak at 464 nm, typical of surface plasmon absorption by Ag nanoparticles. Confocal fluorescence studies showed the embedded Ag nanoparticles in the carbon matrix to have fluorescence property as well. C-AFM measurements have shown that the patterned blend is well conducting due to the interacting Ag nanoparticles, the resistance being two orders less compared to that of polystyrene itself. The higher the beam energy, the lower was the dwell time required to attain a conducting pattern. � 2009 American Chemical Society.

International audience; This article presents the results of an experimental study on the Ti17 titanium alloy, which was carried out to analyze tool wear and the degradation mechanisms of an uncoated tungsten carbide tool insert. Two machining conditions, roughing and finishing, have been studied under different lubrication conditions. The experimental procedure included measurement of the cutting forces and the surface roughness. Different techniques have been used to explain the tool wear mechanisms. Distribution maps of the elemental composition of the titanium alloy and the tool inserts have been created using Energy Dispersive X-ray Spectroscopy (EDS). An area of material deposition on the tool rake face, characterized by a high titanium concentration has been observed. The width of this area and the concentration of titanium, decrease when increasing water jet pressure. The study shows that wear mechanisms, with and without high-pressure water jet assistance (HPWJA) are not the same. For example, for the roughing condition using conventional lubrication, the temperature in the cutting area becomes very high, this causes plastic deformation of the cutting edge which results in its rapid collapse. By contrast, this problem disappears when machining with HPWJA. In addition, the evolution of flank wear (VB) is stabilized with high-pressure lubrication. In this case, the most critical degradation mode is due to notch wear (VBn) leading to the sudden rupture of the cutting edge.

WOS: 000279650900024, Ottoman mortar is the long-established binding material used for centuries and there are many historical buildings as evidence of its use by Ottomans in Erzurum (Eastern Turkey). The physico-chemical and microscopic properties of the Ottoman mortars in Erzurum have been studied in detail as part of an investigation of the mineral raw materials present in the territory of Turkey. For this purpose, SEM, XRD and EDS analyses of six main types of mortars were carried out showing the presence of organic fibers and calcite, quartz and muscovite minerals. The chemical analyses of the specimens showed that higher SiO(2) + Al(2)O(3) + Fe(2)O(3) contents yielded in higher values of hydraulicity and cementation indices. A significant result of this investigation was that mortars with higher hydraulicity and cementation indices had higher compressive strengths. Most probably this is the main reason why historical Ottoman buildings were resistant against serious earthquakes. (C) 2010 Elsevier Ltd. All rights reserved.