Energy Depressive X-ray Research Articles

Synthesis and Characterization of Nylon 6,6-Polyvinyl Alcohol-Based Polyelectrolytic Membrane

This work presents the preparation and investigation of blended nylon (N)/polyvinyl alcohol (PVA)-based polyelectrolytic membranes that are modified with different concentrations of sulfuric acid (SA), chlorosulfonic acid (CSA), and sulfonated activated carbon (SAC) as a filler. Scanning electron microscopy (SEM) micrographs illustrated good membrane homogeneity, and no cracks or phase separation were detected. Chemical interaction between N, PVA, and other membrane components was confirmed by Raman scattering spectroscopy and Fourier transform infrared (FTIR). In addition, the molecular structure is verified by energy depressive X-ray (EDX). Furthermore, water and methanol uptake, gel fraction, and IEC were determined as functions of varied membrane modification components. The results revealed that increasing the portion of SA, CSA and SAC led to an increase in IEC and ionic conductivity values reached 2.12 meq/g–0.076 S/cm for (N/PVA-4.0% SA-4.0% SAC), respectively, and 2.71 meq/g–0.087 S/cm for (N/PVA-4.0% CSA-4.0% SAC), respectively, while the IEC and ionic conductivity value for non-modified N/PVA membrane was 0.02 meq/g and zero, respectively. Such results enhance the potential feasibility of modified N/PVA electrolytic membranes for fuel cell (FC) applications.

Morphology and Corrosion Behavior Study of Thin TiN Films Deposited at Different Substrates by DC Magnetron Sputtering

TiN thin films have been deposited by magnetron sputtering (DC) method under pure argon (100% Ar) gas for different times at 100 oC temperature. Additionally, three substrate types have been used: Low Carbon Steel (LCS), Stainless Steel (SS304) and Silicon of (100) orientation. The composition of the films has been verified by Energy Depressive X-ray Spectroscopy (EDX) analysis for films deposited on Si substrate. This analysis has proved that the nitride films TiN was sub stoichiometry, Scanning Electron Microscope (SEM) image was used to estimate the thickness of TiN/Si film. X-ray diffraction (XRD) measurements were also applied to investigate the orientations of films. All the films (coated samples) have shown enhanced corrosion resistance compared with virgin SS304 and LCS substrate (noncoated sample) in 3.5% NaCl at 25 oC (equivalent to seawater). Morphological behavior was investigated by means of Atomic Force Microscopy (AFM), which indicates very smooth films and consequently related with corrosion resistance using Tafel and the electrochemical impedance spectroscopy (EIS) measurements. It was found the thinner film has revealed higher corrosion resistance and low roughness. DOI: http://dx.doi.org/10.17807/orbital.v13i1.1577

Deposition of TiN and TiAlVN thin films by DC magnetron sputtering

Purpose TiN and TiAlVN films have been prepared by DC magnetron sputtering technique at room temperature. TiN target has been used to deposit TiN thin film under pure argon (100 percent Ar) gas. Additionally, Ti6Al4V alloy target has been used to deposit TiAlVN under nitrogen and argon gas (50 percent Ar and 50 percent N2). In this paper, two substrate types have been used: stainless steel 304 and Si(100). This analysis has confirmed that the nitride films, (TiN/Si) and TiAlVN in both cases, have been produced. Energy Depressive X-ray Spectroscopy (EDX) measurement confirmed that the TiN/Si was stoichiometry, where the N/Ti ratio was about 1 with low oxygen contamination. The results obtained have indicated that the TiAlVN has more resistance to corrosion than TiN film in 3.5 percent NaCl at 25°C (seawater). Both films, TiAlVN/SS304 and TiN/SS304, have shown improved corrosion resistance compared with virgin 304 substrate. Microhardness was carried out using Vickers method; the microhardness values for TiN/SS304 and TiAlVN/SS304 were approximately 7.5 GPa and 25.3 GPa, respectively. The paper aims to discuss these issues. Design/methodology/approach The films were prepared by a DC magnetron sputtering system starting from high pure (99.99 percent) Ti6Al4V target (Al 6wt%, V 4wt% and balance Ti) in plasma discharge argon/nitrogen (50 percent Ar and 50 percent N2) for deposition of TiAlVN film. Pure TiN target (99.99 percent) was used for preparation of TiN film in pure argon plasma. The diameter of target was 50 mm and the power applied for preparation of the two films was 100 W. A cylindrical high-vacuum chamber (Figure 2) made of stainless steel 316, with height 363 mm diameter, was fabricated locally. Scanning electron microscope images have been used to discover the films morphology. The composition of the films has been determined by EDX technique for films deposited on Si substrate. The electrochemical corrosion test was carried out using conventional three-electrode cell of 300 ml capacity by using Voltalab PGZ 301 system (France) using Tafel extrapolation method and electrochemical impedance spectroscopy techniques. Findings TiN and TiAlVN films have been prepared by DC magnetron sputtering technique without heating of the substrates holder. The effects of the composition of nitride films on mechanical and corrosion properties were investigated. The composition of the films has been determined by EDX technique. The effect of using titanium alloy (Ti with Al and V) on the composition and crystalline quality has been investigated. The microhardness is strongly dependent on the addition of the Al and V elements, and it consequently improves mechanical proprieties. The microhardness values for TiN/SS304 were approximately 7.5 GPa and 25.3 GPa for TiAlVN/SS304. They indicate that prepared films prevent the aggressive action of corrosion media. Originality/value TiN and TiAlVN films have been prepared by DC magnetron sputtering method at room temperature. Titanium nitride film, especially TiAlVN, is an effective method to improve the corrosion resistance of SS304. TiAlVN film has exhibited enhanced corrosion resistance and higher microhardness. Independent time-of-flight elastic recoil detection analysis has been used to determine the composition of the film.

Fabrication of Silica Microspheres (HB/A@SI-MNS) for Hafnium and Zirconium Recovery from Zirconyl Leach Liquor

This work describes the synthesis of silica microspheres using sodium silicate obtained as a byproduct in the production of Egyptian Rosetta zircon concentrate. The obtained mesoporous silica microspheres were further modified with aminopropyltriethoxy silane and 2,4-Dihydroxybenzaldehyde to produce Schiff’s base silica sorbent (HB/A@Si-MNS). HB/A@Si-MNS was used for the selective extraction of hafnium from zircon mineral leach liqueur. The fabrication process and surface properties of HB/A@Si-MNS were confirmed by the means of X-ray Fluorescence (XRF), scanning electron microscop (SEM), energy depressive X-ray (EDX), Fourier-transform infrared spectroscopy (FT-IR), and elemental analysis. The uptake behavior of HB/A@Si-MNS towards Zr(IV) and Hf(IV) ions were studied under different experimental conditions. Adsorption curves indicate that the uptake of Zr(IV) and Hf(IV) on HB/A@Si-MNS is a spontaneous, endothermic monolayer system controlled by intraparticle diffusion. Elution efficiencies were found to be 94% and 98% for Zr(IV) and Hf(IV), respectively. The regenerated HB/A@SI-MNS showed uptake capacity comparable to that of fresh ones over 3 cycles. The results of the extraction of Hf(IV) than Zr(IV) from Rosetta zircon concentrate show that HB/A@SI-MNS has a preferential selectivity towards Hf(IV) than Zr(IV). Therefore, the studied material may be promising for the selective separation of Hf(IV) from Zr(IV).

Application of Nuclear Analytical Techniques in Elemental Characterization of Wadi El-Nakhil Alabaster, Central Eastern Desert, Egypt

Instrumental neutron activation analysis (INAA) is a powerful technique for trace element determination in rocks. Nine alabaster samples were collected from Wadi El-Nakhil located at the intersection of lat. 26°10′50′′N and long. 34°03′40′′E, central Eastern Desert, Egypt, for investigation by INAA and Energy Depressive X-Ray Fluorescence (EDXRF). The samples were irradiated by thermal neutrons at the TRIGA Mainz research reactor at a neutron flux of 7 × 1011 n/cm2·s. Twenty-two elements were determined, namely, As, Ba, Ca, Co, Cr, Sc, Fe, Hf, K, Mg, Mn, Na, Rb, U, Zn, Zr, Lu, Ce, Sm, La, Yb, and Eu. The chemical analysis of alabaster indicated having high contents of CaO and MgO and LOI and low contents of SiO2, Al2O3, Na2O, K2O, MnO, and Fe2O3.

Characterisation of Ti-6Al-4V Reciprocating Sliding Wear Test Behaviour

Sliding contact will experience wear in majority of mechanical components during their service life where it reduces the performance of the components. The capability to predict the evolution of reciprocating wear scars, such as the scar’s width and depth, would be a valuable tool when designing mechanical components. Wear scar mechanism behaviour is characterised during stabilized cycle reciprocating sliding wear test of Ti-6Al-4V investigated using pin-on-flat arrangement under variable duration of sliding. The test samples were analyzed using profilometer test, optical microscopy test, Scanning Electron Microscopy (SEM) test, Energy Depressive X-ray (EDX) test and Vickers Hardness (HV) test. Stabilised high number of cycles shows low wear rate and initiation period of low cycles produced higher wear rate.

Ball-Milled Graphite-Tin Composite Anode Materials for Lithium-Ion Battery

Lithium alloying compounds as an anode materials have been a focused for high capacity lithium ion battery due to their highenergy capacity and safety characteristics. Here we report on the preparation of graphite-tin composite by using ball-milling in liquid media. The composite material has been characterized by scanning electron microscope, energy depressive X-ray spectroscopy, X-ray diffraction and Raman spectra. The lithium-ion cell made from graphite-tin composite presented initial discharge capacity of 1065 mAh/g and charge capacity 538 mAh/g, which becomes 528 mAh/g in the second cycle. The composite of graphite-tin with higher capacity compared to pristine graphite is a promising alternative anode material for lithium-ion battery.

Improving the corrosion resistance and mechanical property of 45 steel surface by laser cladding with Ni60CuMoW alloy powder

Laser cladding Ni60CuMoW composite coating was fabricated on 45 steel surfaces using a synchronization powder feeding technique by 6kW transverse-flow CO2 laser apparatus. The effect of laser power and tempering treatment process on corrosion resistance of the cladding coating was investigated. The microstructure and mechanical property were analyzed by X-ray diffractometer (XRD), scanning electron microscope (SEM), energy depressive X-ray spectroscopy (EDX), microhardness tester and PS-268A electrochemical system. The XRD and EDX results show that the cladding coating is mainly composed of γ (Ni, Fe), solid solution phase (Ni, Cu), compounds Ni31Si12, Cr5B3, CrB, Ni3B, FeNi3, M23C6 (Cr23C6 or (Fe,Ni)23C6) and a small amount of WC or W2C. With the increase of laser power, corrosion resistance and microhardness of the cladding coating have been improved. Compared with the untreated substrate, the maximum corrosion potential of single-track coating in 3.5% NaCl saturated solution increased by 136.2mV, and the lowest corrosion current density decreased by two orders of magnitude. The mean microhardness of laser cladding samples increased by 5.17, 4.90 and 4.89 times, respectively. The corrosion potential of three-track coating increased by 437.6mV and corrosion current density decreased by one order of magnitude than that of single-track coating's. After tempering by 600°C heat treatment, the primary dendrite and block eutectic in composite coating became more uniform, the maximum corrosion potential increased by 45.5mV and corrosion current density also decreased significantly.

Photocatalytic behavior of TiO 2 nanoparticles supported on porous aluminosilicate surface modified by cationic surfactant

In order to utilize the photocatalytic function of TiO 2 nanoparticles in materials manufactured from organic polymeric compounds, such as paper, resins, and textiles, TiO 2 nanoparticles supported on aluminosilicate, which contained 1, 5, and 10 wt% of TiO 2 were prepared by mixing commercial TiO 2 nanoparticles and porous aluminosilicate at pH 7 in a cationic surfactant aqueous solution. Most of the supported TiO 2 nanoparticles on the aluminosilicate surface were observed by TEM–EDS (energy depressive X-ray spectroscopy) analysis. TiO 2 nanoparticles supported on aluminosilicate reduced the formaldehyde concentration from 20 to 0 ppm after UV irradiation for 20 h; the reduction of formaldehyde concentration under UV irradiation was obviously different from that in the dark. Moreover, a paper mixed with 20 wt% of TiO 2 nanoparticles supported on aluminosilicate bleached the stains colored with cigarette tar after UV irradiation for 6 h. However, the paper maintained its initial tensile strength even after UV irradiation for 1 year; in contrast, the paper mixed with a simple dry mixture of TiO 2 powder and aluminosilicate lost approximately half of its initial tensile strength after a year. TiO 2 nanoparticles supported on aluminosilicate could exhibit photocatalytic activity without decomposing the organic polymeric compounds.

Preparation, characterization and electrical properties of spinel-type environment friendly thick film NTC thermistors

Environment friendly thick film NTC thermistors based on spinel-type semiconducting electroceramics of different compositions Mn 1.85Co 0.8Ni 0.35O 4, and Mn 1.85Co 0.8Ni 0.35O 4 + RuO 2 were fabricated on alumina substrate. The basic bulk ceramics and the fired thick films were characterized by thermo-gravimetric analysis, X-ray diffraction, and scanning electron microscopy with energy depressive X-ray analysis. Thick film samples showed compact and homogeneous microstructure. The electrical parameters of the planar thick film NTC thermistors were determined. Depending on the ceramic composition, the prepared thick film NTC thermistors showed room temperature resistance in the range of 6–168 MΩ. The values of thermistor constant, β 25/300 ranged from 3600 to 4900 K.

LIGA fabrication of nanocrystalline Ni–W alloy micro specimens from ammonia-citrate bath

Ammonia-citrate bath has been investigated for the deposition of nano crystalline Ni–W alloy micro components using the LIGA process. First the bath stability and deposit characteristics were studied. Fabrication of micro specimens were then carried out on silicon substrates covered with novolac as well as thick PMMA resist for LIGA. Effects of different parameters like current density, nickel ion and tungsten ion concentration in the bath, deposition time etc. on the deposit characteristics and current efficiency were studied. The deposited Ni–W samples were characterized by scanning electron microscopy, energy depressive X-ray spectroscopy, light optical microscopy and X-ray diffraction. Results show that during a few tens of hours of deposition, ammonia loss from the covered bath used is minimal and the bath remains stable. Selection of proper bath and deposition parameters allows a window for the deposition of crack free, thick, nano crystalline nickel–tungsten alloys. Using the optimum parameters, it has been possible to fabricate Ni-12 at% W micro tensile specimens with a nominal thickness of 120 μm by the LIGA process.

Development of nickel coatings by TiN interlayer

Nickel coating was electrodeposited on steel substrate using Watt's bath. With an aim to improve the corrosion resistance of Ni coating, an additional TiN interlayer of approximately 300 nm thick and average grain size 22 nm was deposited on the substrate using a plasma focus device (PFD). The electrochemical behavior of single layer TiN deposited on steel substrate and Ni coatings were studied in 3.5% NaCl solution. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) combined with an energy depressive X-ray (EDX) microanalyzer were applied to characterize the coated samples. The potentiodynamic polarization tests showed lower corrosion current density and higher polarization resistance for the coatings with TiN interlayer. Similarly, Ni coatings with TiN interlayer showed about six times improved corrosion resistance in 1 M HCl as compared to the samples without TiN interlayer. Salt spray test has been used to determine the performance of coated samples in 5% vapor of NaCl.

On changes in bed-material particles from a 550 MWth CFB boiler burning coal, bark and peat

This paper presents our observations on coating build up, morphology and the elemental composition of bed-material particles collected from a 550 MWth CFB boiler burning coal, bark and peat fuel/fuel mixture. The special focus was on the changes of the elemental composition of coating layer on bed-material particles when different fuels were burned. The results were obtained using a scanning electron microscope coupled with an energy depressive X-ray analyser (SEM/EDX). The results clearly show that properties of bed-material particles are a result of complex interaction between the fuels burned previously, and the fuels used at the time of sampling.

Effects of laser welding on bond of porcelain fused cast pure titanium

To investigate the influence of the laser welding on bond of porcelain fused to cast pure titanium. Twenty cast titanium plates were divided into two groups: laser welded group and control group. The low-fusing porcelain was fused to the laser welded cast pure titanium plates at fusion zone. The bond strength of the porcelain to laser welded cast pure titanium was measured by the three-point bending test. The interface of titanium and porcelain was investigated by scanning electron microscopy (SEM) and energy depressive X-ray detector (EDX). The non-welded titanium plates were used as comparison. No significant difference of the bond strength was found between laser-welded samples [(46.85 +/- 0.76) MPa] and the controls [(41.71 +/- 0.55) MPa] (P > 0.05). The SEM displayed the interface presented similar irregularities with a predominance. The titanium diffused to low-fusing porcelain, while silicon and aluminum diffused to titanium basement. Laser welding does not affect low-fusing porcelain fused to pure titanium.

Immiscible silver–nickel alloying nanorods growth upon pulsed-laser induced liquid/solid interfacial reaction

Nanorods of the immiscible alloying silver–nickel were synthesized by pulsed-laser induced liquid/solid interfacial reaction (PLIIR). Typical diameters of these nanorods were in the range of 30–50 nm, and lengths were in the range of 300–500 nm. Transmission electronic microscope (TEM) equipped with energy depressive X-ray spectrometer (EDS) and selected area diffraction (SAD) were employed to characterize these nanorods. The analysis results showed that the prepared Ag–Ni alloying nanorods were single crystals with fcc structure. Eventually, we proposed the growth mechanism of the immiscible alloying nanorods upon PLIIR, in which both liquid and solid were simultaneously involved.

Wear mechanism of CBN cutting tool during high-speed machining of mold steel

Wear behavior of cubic boron nitride (CBN) cutting tool when cutting P20 tool steel was investigated. Oblique cutting tests were performed on a CNC lathe using five speeds, namely, 240, 600 and 1000 m min −1. The CBN cutting tools were found to be superior to tungsten carbide (WC) tools. Fourfold increase in productivity and significant reduction in chipping and cratering was achieved for CBN as compared to WC. Wear, as the width of the wear land (VB), was monitored at selected time intervals; furthermore, topography of worn surfaces was performed, using a profilometer. Wear characterization of the rake and the flank surfaces as well as of the collected chips was conducted using a scanning electron microscopy (SEM), backscattered electron imaging and energy depressive X-ray (EDX). It was found that deformation in the chips occurs by localized shear deformation and the dominant wear mechanism at all speeds used was identified to be diffusive wear. At a 1000 m min −1 cutting speed, a secondary wear mechanism was identified, which is melt wear, i.e., formation of low melting point Cr and Mn compounds with the tool material and the subsequent ejection from the cutting zone.

Apatite formation on TiO 2 anatase microspheres

Titanium dioxide (TiO 2) coatings have been long considered as biocompatible interfaces to promote the physico-chemical bonding between the bone tissues and implant material (e.g., titanium and stainless steel). Monodispersed TiO 2 (anatase, the low temperature polymorph of TiO 2) microspheres, produced in the form of colloidal precipitates, were deposited on different substrates and apatite formation was induced on the resulted surface by immersing the coated substrates in simulated body fluid solution. Analytical and microstructural investigations, conducted by X-ray diffraction, energy depressive X-ray spectroscopy and scanning electron microscopy techniques, showed considerable higher rates of apatite formation, in vitro, on the anatase microspheres compared to the sol–gel-derived thin films of the same oxide. We concluded that the particular surface morphology of the packed TiO 2 microspheres, promotes a faster apatite formation in vitro.

Temperature-dependent surface topography analysis of Illinois class F fly ash using ESEM and AFM

The evolution of particle surface morphology of Illinois Class F fly ash with calcination temperature was monitored using atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM). Significant new information on particle chemical composition and morphology was obtained using ESEM and AFM. Particularly, AFM provides detailed information on the roughness of the particle, which increased with the calcination temperature. Noticeable changes in fly ash surface morphology as a function of temperature has been noticed using ESEM. Thermal treatment of fly ash particles produces a very rough surface, often resulting from the formation of surface deposits, as well as pitting of the particle surface. Energy depressive X-ray analysis provided detailed information on the chemical nature of fly ash particles. No significant changes in elemental concentration were noticed, although oxygen concentration reduced upon calcination. A correlation of the surface microscopical quantitative information with the elemental analysis is presented, which can be very helpful for engineering applications where fly ash particles are used as metal filler.

Comparison of CO 2, Nd:YAG and high power diode lasers for the ablation of tile grout

Process feasibility of a laser-based grout removal process and the effects thereof on the processing parameters have been successfully examined using three different lasers: CO 2, Nd:YAG and HPDL (high power diode laser). The grout removal rate was found to increase linearly with laser power level. In contrast, it was affected very little by laser traverse speed. The optimum removal rate was obtained with the CO 2 laser and this occurrence was believed to be due to the CO 2 laser’s wavelength. Surface morphological and material characterisation on the laser-removed grout was carried out. Depending on the laser used, colour ranged from white to dark grey. Significant differences between the untreated and laser-treated samples, as well as between the samples treated by the different lasers, were observed. The CO 2 laser produced relatively larger sized particles, with the Nd:YAG and HPDL generating finer particles exhibiting a similar appearance. An energy depressive X-ray (EDX) and an X-ray diffraction analysis (XRD) of the epoxy grout chemical composition before and after the laser treatment revealed that CaCO 3 (limestone) was decomposed to give CaO and CO 2 during laser interaction. The existence of SiO 2, Ti and dolomite was also found in the original grout material. thermogravimetric and differential thermal analysis (TG–DTA) identified a sequence of three stages in the thermal history of the epoxy grout.

Iron in olive tree leaves in the Mediterranean area

In this paper we used the technique of X-ray fluorescence by dispersion in energy in order to study a phytopathology named “sooty mould” in olive tree leaves in the Mediterranean area. Samples studied included leaves which were infected and non-infected by sooty mould. Energy depressive X-ray fluorescence showed a significant increase in the amount of Fe in the affected leaves when compared to leaves that don’t have this pattern of black material. We suggest here that a treatment for this condition may be based on a method that deprives these organisms of the Fe that they apparently need to survive. The average Fe concentration obtained for the infected olive tree leaves was 80 ppm, while the non-infected ones showed no measurable Fe presence.