Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : XRD

Structural Characterization of (Mg(1-x)pbxO)-NPs by Modified Pechini Method

Israa A. Najem; Fadhil Abd Rasin; Shaker J. Edrees

Engineering and Technology Journal, 2022, Volume 40, Issue 6, Pages 11-20
DOI: 10.30684/etj.v40i6.2147

The structural characterization was discussed in the present paper of the pure MgO nanoparticles and the doped (Mg(1-x)pbxO) nanoparticles specimens, where (0 ≤ x ≤ 0.03). The modified Pechini method was used to prepare all the specimens. From (DTA), the convenient temperature of decomposition from Mg(OH)2 to MgO was above 375°C. The structure investigation (XRD) revealed that all the specimens have identical space groups and index well to cubic structures. The obtained crystallite size by Scherrer''s equation was increased with increasing the fraction of doping except for (Mg0.97Pb0.03O) due to the formation of PbO oxide. The molecular vibration by FTIR demonstrated that all the pure and doped specimens have the same framework. As the incorporation of Pb2+ ions increases, the bands get broader, and the intensities increase in the ranging 800-400 cm-1 due to vibrations of O-Mg and O-Pb bands, respectively.

Preparation and Characterization of NiTi/PVA Nanofibers by Electrospinning

Akram R. Jabur; Randa Al-Tuhafi

Engineering and Technology Journal, 2021, Volume 39, Issue 11, Pages 1674-1680
DOI: 10.30684/etj.v39i11.2272

NiTi alloys are widely used in biomedical applications for their unique properties particularly the shape memory effect, superelasticity, and biocompatibility. In this research, NiTi/PVA composite nanofibers are fabricated by electrospinning technique, using a novel method of producing NiTi ultrafine particles by immersing amorphous NiTi alloy in dilute aqua regia solution. The NiTi particles are successfully embedded in the PVA matrix. The produced NiTi particles are analyzed by X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS), and Particle size analyzer. The XRD pattern of ultrafine NiTi particles shows much better phases as compared to the XRD pattern of the amorphous NiTi alloy sample. The morphology of the produced NiTi/PVA composite nanofibers are characterized by Field emission scanning microscope (FESEM), and Energy dispersive spectrometry (EDS). The test results show regular continuous smooth bead-free nanofibers.

Gas Sensitivity of ITO Composite Prepared by Sol-Gel Method

R. J . Halbos; S. AL-Algawi; R.T. Rasheed

Engineering and Technology Journal, 2017, Volume 35, Issue 10, Pages 981-986
DOI: 10.30684/etj.35.10A.3

Indium oxide and indium tin oxide composite (ITO) were prepared by sol-gel dip-coating (SGDC) technique. The particles annealed at (200 ◦C, 400 ◦C). The structure and surface morphology of particles were characterized by X-ray diffraction (XRD), Atomic Force Microscope (AFM), FT-IR and UV/visible measurements. The XRD and AFM indicate decreasing in the particle size and improve of optical and electrical properties of composite with increasing of tin oxide addition. The hall measurement were used to obtain information about the type of conductivity of indium oxide and indium tin oxide thin films and carrier concentration and mobility and resistivity, the results of Hall measurements show that the In2O3 and ITO composite have n-type. The thin film of composite ITO at composition (80:20) mole ratio has high sensitivity toward CO gas compared with pure indium oxide.

Use of Nano-Magnetic Material for Removal of Heavy Metals from Wastewater

G.K. Salman; A.J. Bohan; G.M. Jaed

Engineering and Technology Journal, 2017, Volume 35, Issue 9, Pages 903-908
DOI: 10.30684/etj.35.9A.6

The reason of this study is to consider the removal of heavy metal lead (Pb) and cadmium (Cd) in wastewater by magnetic material using ferrite. It has been use batch experiments and operating condition are, ph(10,7and5) and time (20, 40, 60.80.100, 120) min and temperature (30) 0C after that we find the optimum condition to remove heavy metal. heavy metal in water detected by using Atomic Absorption (AA) before and after adding Cu-ferrites powder while the Cu-ferrites was characteristic by XRD and SEM ,result indicate that Cu-ferrites powder spinel structure and the particle size in range (30-40)nm ,and explain antimicrobial effectiveness of ferrites material from effect on gram positive and negative bacteria and the results appeared ability of copper ferrites to inhibition growth of both E. coli as example of gram negative bacteria and S. aureus as example of gram positive bacteria while was the E. coli survival rate of all ferrite nanoparticles concentration is more than the S. aureus survival rate , the percentage survival of bacteria was ( 35 , 20 , 12 , 5 %) in (0.625 , 1.25 , 2.5 , 5 mg/ml) concentration of microorganisms E.coli and ( 28 , 15 , 8 , 3 %) in (0.625 , 1.25 , 2.5 , 5 mg/ml) concentration for bacteria Staph. Aureus

Effect of Al2O3 Powder on Some Mechanical and Physical Properties for Unsaturated Polyester Resin Hybrid Composites Materials Reinforced by Carbon and Glass Fibers

Reem Alaa Mohammed

Engineering and Technology Journal, 2016, Volume 34, Issue 12, Pages 2371-2379
DOI: 10.30684/etj.34.12A.18

This research is a study of the effect of Al2O3 powder on physical and mechanical properties of the polymer hybrid composites based on unsaturated polyester resin reinforced with carbon and glass fibers. The samples were made by a hand lay-up method according to ASTM standard for various volume fractions of additives. The polymer composites materials reinforced with carbon and glass fibers are the most used in manufacture of components such as pip, part of aerospace, and leisure industries and automotive.The polyester resin matrixwas strengthened with 3% carbon and glass fibers with 1%, 3%, 5%, 7% Al2O3 powders. The water absorption, hardness (shore D), impact test, and flexural strength properties are studied. The results show the specimens (UP+3%C.F+7%Al2O3) and(UP+3%G.F+7%Al2O3) had the maximum hardness (shore D) and water absorptionwhen compared withunfilledpolyester resinspecimen, it can be observed that the specimens(UP+3%C.F+5%Al2O3) and (UP+3%G.F+5%Al2O3) have maximum impact strength and flexural strengthcompared with specimens (UP+3%C.F+7%Al2O3)and (UP+3%G.F+7%Al2O3) .

Effect of Hydrothermal Reaction Temperatures on Structural and Optical Properties of ZnS Nanoparticles

Selma M .H. Al-Jawad; Mukhlis M .Ismail; Sora Emad

Engineering and Technology Journal, 2016, Volume 34, Issue 6, Pages 808-819

A ZnS nanoparticle was prepared using hydrothermal interaction of zinc acetate with Thiourea in different reaction temperatures (170oC, 180oC, 185oC, 190oC). The structural characterization of synthesized nanoparticle was determined by X-ray diffraction (XRD) which showed a hexagonal structural of ZnS. Scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analysis were confirmed that the morphology and elemental analysis was formed ZnS nanoparticle. Absorption study has been carried out using UV-VIS spectrophotometer to determine the band gap of ZnS nanoparticle. The optical energy band gap was changed at values equal to (4.16, 4.46, 4.1 and 4.35eV) with different hydrothermal temperatures at (170oC, 180oC, 185oC and 190oC) respectively. However, these values of energy gaps for ZnS nanoparticles are blue shift and larger than that bulk value due to quantum confinement. Fourier Transform Infrared Spectra (FTIR) is recorded in an FTIR spectrometer to verify the presence of ZnS powder. The particle size of ZnS calculated was ranged between 3.5 to 3.9 nm according to Sherrer's equation and the results were compatible when using Effective Mass Approximation (EMA).

Structural , Morphological and Electrical Properties of AgSbSe2 Thin Films

Bushra A.Hasan; Issam M. Ibrahim

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1283-1289

AgSbSe2thin films with different thicknesses (100,300,500, and 700nm) have been deposited by single source vacuum thermal evaporation onto glass substrates at ambient temperature to study the effect of thickness on its structural morphology, and electrical properties. The X–ray diffraction patterns of AgSbSe2thin film show that with low thickness (t=100,300 and 500nm) have amorphous structure convert to polycrystalline structure with increase thickness to 700 nm..AFM measurements show that the average grain size increases while the average surface roughness decreases with the increase of thickness. The DC conductivity of the vacuum evaporated AgSbSe2thin films was measured in the temperature range (298-473)K and was found to increase on order of magnitude with increase of thickness. The plot of conductivity with reciprocal temperature suggests, there are two activation energies Ea1, andEa2 for AgSbSe2for all and thicknesses which decrease with increasing thickness. The electric carrier concentration and mobility show opposite dependence upon thickness.

Preparation and Study Effects of Stirring Time on the Structural and Optical Properties of SnO2 Nanoparticles

T.A.AL-Dhahir; Noor A. Hameed; Ziyad Tariq Khodair; Tagreed. M. Al-Saadi

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 960-971

Tin Oxide nanoparticles (SnO2-NPs) were prepared by mixing (SnCl4.5H2O) with distilled water at room temperature. The samples were characterized for their crystalline structure, morphology and chemical structure by using X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). The XRD data and Dicvol 91 software analysis the crystal system was found to be tetragonal structure for samples prepared under stirring time for (24,48,72) h with (a=4.745 , c=3.184), (a=4.768 , c=3.255) and (a=4.776 and c=3.257) respectively. The average of crystallite size calculated by using SEM it was 9.45 nm, 14.7 nm and 21.5 nm, for the same times, previously mentioned of stirring. The effect of stirring time on the crystal lattice distortion ratio, specific surface area and dislocation density was discussed. The optical band gap values of SnO2-NPs were calculated to be about 3.4eV, 3.37eV and 3.2eV under stirring time for 24 h, 48 h and 72 h respectively by optical absorption measurement.

Study of ZnO, SnO2 and Compounds ZTO Structures Synthesized for Gas-Detection

Farhad M. Othman; Alaa A. Abdul-Hamead; Alaa S. Taeeh

Engineering and Technology Journal, 2015, Volume 33, Issue A6, Pages 1328-1340
DOI: 10.30684/etj.33.6A.4

Semiconductor-based metal oxide gas detector of five mixed Z:S from zinc chloride salt (0,25,50,75,100%) ratios with tin chloride salt, were fabricated on glass substrate by a spray pyrolysis technique with thickness were about ( 0.2 ±0.05 µm) using water soluble as precursors at a substrate temperature 500 Cº±5, 0.05 M ,and their gas sensing properties toward (CO2 , NO2 and SO2 gas at different concentration (10,100,1000 ppm) in air were investigated at room temperature which related with the petroleum industry.
Furthermore structural and morphology properties was inspecting. Experimental results show that the mixing ratio affect the composition of formative oxides (ZnO,Zn2SnO4,Zn2SnO4+ZnSnO3,ZnSnO3, SnO2) ratios mentioned in the above respectively, and related with the sensitivity of the tested oxidation gases.

Investigation of Laser Assisted Etching for Preparation Silicon Nanostructure and Diagnostic Physical Properties

Zahraa J. Abdulkareem; Uday M. Nayef; Kadhim A.Hubeatir

Engineering and Technology Journal, 2015, Volume 33, Issue 4, Pages 595-601

In this paper; nanostructure porous silicon (PS) was prepared by using photo-electrochemical etching (PECE) of n-type silicon at 10 & 30 mA/cm2 etching current density for 10 minute. X-ray diffraction (XRD) confirms the formation of porous silicon and the crystal size is reduced toward nanometric scale. The Atomic Force Microscope (AFM) investigation shows the sponge like structure of PS, the width of surface pits and surface roughness increase with etching current density.Finally, the Fourier Transform Infrared (FTIR) illustrates the PS layer have large amount of dangling bonds.

Characteristics Study of ZnO Thin Films by Rapid Thermal Oxidation Treatment Technique

Uday Muhsin Nayef; Mohammed Jamal Jasim

Engineering and Technology Journal, 2015, Volume 33, Issue 1, Pages 37-44

In this paper preparation of good quality transparent conductive ZnO thin films by post-oxidation of vacuum evaporated Zn, on glass and silicon (p-type) as substrates, the oxidation was achieved in a short time (90 sec) which is known as rapid thermal oxidation. One growth parameter has been considered to specify the optimum conditions the film thickness are (200,300,400 &500 nm).
The XRD spectra revealed a high oriented grain in the (002) lattice system which is hexagonal wurtzite and proved that the ZnO films have a polycrystalline structure. Also, the morphological properties of ZnO films show that all films have a homogeneous surface morphology and it appears, to change significantly as a function of thickness.The energy gap of ZnO films decreases as the thickness increases. The FTIR spectra indicate the existence of the distinct characteristic absorption peak at 472.56cm-1 for Zn-O stretching mode.
Study of effect I-V and C-V measurements of ZnO films with the increase thickness. The photovoltaic properties confirmed that the photovoltaic depends strongly on the bias voltage and the amount of current produced by a photovoltaic device which is directly related to the number of photons absorbed. C-V results demonstrated that the fabricated heterojunction is of abrupt type. Also, the width of the depletion layer (w) follows the same behavior (V_bi ) decreased while the charge carrier density (N_d ) was increased with the thickness increase.

Fabrication and Characterization of ZnO Gas Sensor

Alaa A. Abdul-Hamead; Farhad M. Osman; Alaa S. Taeeh

Engineering and Technology Journal, 2014, Volume 32, Issue 9, Pages 2303-2312
DOI: 10.30684/etj.32.9A16

In this paper thin films of zinc oxide ZnO was prepared by spray pyrolyess method with thickness were about ( 0.1 ±0.05 µm) on n-type silicon substrates at different deposition temperature (300,400,500) C°, from zinc chloride at concentrations (0.05,0.1) M as a sensor for pollutant gases like CO2 , NO2, and H2S related with oil manufacture .
The crystallinity and morphology of the films were characterized by XRD, and optical microscopy was done on prepared films , addition to sensitivity to polluting gases previously mentioned at different test temperature (10-50) C°.
Result shows that the crystallization increased by increasing deposition temperature(substrate temperature), and the sensitivity increased by rising both of the gas concentration or temperature.

Structural,Morphology and PL Properties of ZnO Film Deposition on Porous Silicon

Uday Muhsin Nayef; Mohammed Waleed Muayad

Engineering and Technology Journal, 2014, Volume 32, Issue 6, Pages 1106-1110
DOI: 10.30684/etj.32.6B.9

ZnO thin film was deposited on glass and porous silicon by spray pyrolysis technology with fixed parameters consist (substrate temperature 400Co, deposition rate 100nm/min), and the measurements of structural (XRD), morphology (AFM) and photoluminesces (PL) refer to good growth of ZnO after using porous silicon more than using glass and that's come from sponge like structure of porous silicon and large spastic area of porous silicon (about 500m2/cm3).

Dependence of Structure and Optical Characterization of (Bi2Te3) Films Prepared by Flash Evaporation on Annealing Temperatures

Hussain Kh.Rasheed; Ghuson H .Mohamed; Khalil I. Inad

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 729-736
DOI: 10.30684/etj.32.4B.13

In this study Bi2Te3 stoichiometry alloy was fabricated by using melting method in the electric furnce at temperature (580 0C for 6h). Thin films (Bi2Te3 ) were deposited by flash technique under vacuum 10-5 Torr . The thickness measured of films was 500nm .the influence of annealing temperature (100 -200) 0C was studied structure and optical properties of Bi2Te3 thin films. Structural properties for thin films of Bi2Te3 were investigated by XRD and AFM analysis. The XRD analysis of alloy show that poly crystalline phase for Bi2Te3 stoichiometry while the films prepared were amorphous at room temperature and phase transition to polycrystalline under annealing with preffered orientation at (015) corresponding to( 2θ =27.639) .FT-IR measured were studied for Bi2Te3 in range of (400-4000 )cm-1 under annealing temperature and this measured show that decreasing of Eg with increasing annealing temperature ,this can be interpreted in term improved the crystal structure.

Recycling of an Effluent Soot from Kademia Diesel-Power Plant as a Carbon Source for the Synthesis and Characterization of NanoCarbon

Adel Sharif Hamadi

Engineering and Technology Journal, 2014, Volume 32, Issue 3, Pages 386-395
DOI: 10.30684/etj.32.3B.1

Soot obtained as an effluent from Kademia diesel-power station was recycled and utilized as feedstock for preparation of nano carbon particles. The porosity, surface area analysis featured by BET N2 adsorption, proximate analysis, Fourier Tranform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) were employed for the structural and morphological characterization of the halocarbon formed.
Ultimate analysis of the fuel oil samples indicate that the H/C ratio of nanospheres is less 0.085 which is an indication of crystallization in the nanomaterial formed.
The results obtained from BET analysis had specific surface area increases to 50 m2/g, comparing with 28 m2/g of that the raw soot. SEM results shows a variations in size and shape of nanocarbon particles formed. The FTIR spectrum of soot shows characteristic signals in the range of 400-4000 cm-1 where corresponding to SO4 2- (600 cm-1), NO3 - (850 cm-1), CO3 2- (900 cm-1), SiO4 4- (1050 cm-1), C–OH aromatics (1250 cm-1), NO3 - (1300 cm-1), CO3 2- (1650 and 1720 cm-1), C=CH alkenes (2930 cm-1), and C – OH alcohols (3400 and 3550 cm-1). XRD investigation indicates the presence of large amount of amorphous material in association with nanocarbon at moderately high intensity broad peak; 2θ=23.5140o, where at the low intensity; 2θ=48.6389o indicate of the low quality of nanomaterial presented in the soot.

Fe Analysis of Residual Stresses Induced by Spot Welding of Stainless Steel Type Aisi 316

Ahmed N. Al-Khazraji; Samir A. Al-Rabii; Ali Hussein F. Al-Jelehawy

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 365-384
DOI: 10.30684/etj.32.2A.7

Specimens of the as-received stainless steel type 316, according to AISI standard, in form of sheet with 1.5 mm thickness were first spot welded and thenshot peened to obtain the influence of shot peening process on the residual stresses induced by spot welding process. X-Ray Diffraction (XRD) method was used to measure the residual stresses. Also, a finite element method (FEM) was employed by ANSYS software version 11 to achieve the simulations for transient thermal analysis and residual stresses analysis in all cases. In addition, the temperature dependency of materials properties was used to assess its effects on the final residual stress results. A comparison showed a very good agreement between the experimental and the numerical results due to the total elimination of tensile residual stresses and creating the compressive type instead.

Properties of Nano Thin Film Composed of Nan Crystalline Zro2 Prepared by (SOL - GEL) Method

Kassim Mohammed Sahan; Aqel Mashot Jafar

Engineering and Technology Journal, 2014, Volume 32, Issue 1, Pages 23-32
DOI: 10.30684/etj.32.1B.4

Nano-crystalline ZrO2 was prepared by sol-gel method and deposited on glass substrate by dip-coating technique method in the room temperature. ZrOCl2 was dissolved in a solvent mixture composed of H2O2 and ammonia. The dissolving reaction produced a colorless, transparent peroxozirconium complex solution. The mean nanocrystalline size was about 7.55 nm. The zirconium film thus obtained was transparent 90% with 5.03 eV band gap. Atomic force microscopy (AFM), X-ray diffraction and (UV-Vis) used to determine the properties of the thin film. The as-deposited thin film was of high purity of ZrO2 and good adhesion to the substrate. The annealing was caused crystallization of tetragonal and monoclinic phase present in the zirconia at 550°C in air. The film showed very flat surfaces consisting of nanoparticles with particle size of ranging (2-10 nm).

Fabrication of Tio2 and V2o5 Thin Films by Powder Coating Technique

Mohammed S. Hamza; Alaa Aladdin; Shatha Kazem

Engineering and Technology Journal, 2013, Volume 31, Issue 16, Pages 3194-3202
DOI: 10.30684/etj.31.16A.14

Titanium dioxide (TiO2) and vanadium oxide (V2O5) in different mixing percentage
(100, 50, 0)% from them powders as thin film on substrate of glass .the coating
thickness was ( 0.37 ±0.03 μm ).
Thin films were inspection by microphotographs with scanning electron microscopy
(SEM) and x-ray diffraction (XRD).
The results showed that thin films was prepared crystalline and also the compound
(tio2, v2o5), and the structure was regular and smooth.

Study of Some Properties of SnO2 Thin Film

Alaa A. Abdul-Hamead

Engineering and Technology Journal, 2013, Volume 31, Issue 12, Pages 2292-2298
DOI: 10.30684/etj.31.12A.7

In this paper thin films of Tin oxide SnO2 was prepared by spray pyrolyess method
on glass and pure silicon substrates at deposition temperature(300,400,500) Cᵒ, from Tin
chloride at concentration(0.1 M) .
The films thickness were about 0.1 ±0.02 μm and Atomization rate was about
(1 nm/s).
The test was done on prepared film by XRD and optical microscopy addition to
sensitivity to nitrous oxide gas at different test temperature (25, 50, 75,100) Cᵒ.
Result shows that the crystallization increased by increasing deposing temperature
and the sensitivity increased by rising the gas concentration or temperature.

Synthesis and Study of the Structural and Electrical Conductivity for Nanocrystalline PbS Thin Films

Ali M. Mousa; Selma M. Al-Jawad; SuadM.Kadhim Al-shammari

Engineering and Technology Journal, 2013, Volume 31, Issue 6, Pages 714-719
DOI: 10.30684/etj.31.6B.3

Structural and electrical properties of prepared nanocrystalline lead sulfide thin films were studied which deposited on glass substrates by chemical bath deposition (CBD) techniques. The films were obtained in a reaction bath at times of (15, 30, 45,60and90) min. The X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements confirmed that the thin films grown by this technique had good crystalline cubic structures and homogeneous surfaces. The dc electrical conductivity found in the range of 10-6 -10-5 (Ω.cm)-1.

Structural and Optical Characterization of NanocrystallinePbs Thin Films Synthesized by CBDMethod

Ali M. Mousa; Selma M. Al-Jawad; Suad M.Kadhim Al-shammari

Engineering and Technology Journal, 2013, Volume 31, Issue 5, Pages 603-612
DOI: 10.30684/etj.31.5B.4

Nanocrystalline PbS thin films have been deposited on glass substrates by Chemical Bath Deposition (CBD) technique using lead acetate ,KoH, thiourea and T.E.A. The films were btained in a reaction bath at times of (15 ,30 ,45 ,60 and 90)min. Structure and surface morphology of thin films were characterized by X-ray diffraction and scanning electron microscopy (SEM). XRD indicates that the films have cubic structure. The crystallite size of the films were found to vary from (4.9 to 11.3 nm).The band gaps of the nanocrystalline PbS were determined from UV-Vis spectrophotometer and were found to be in the range( 1.72 -2.4 eV).

Structural, Chemical and Morphological of Porous Silicon Produced by Electrochemical Etching

Amna A. Salman; Fatima I. Sultan; Uday M. Nayef

Engineering and Technology Journal, 2012, Volume 30, Issue 5, Pages 855-867
DOI: 10.30684/etj.30.5.12

In this paper, the nanocrystalline porous silicon (PS) films is prepared by electrochemical etching of p-type silicon wafer with different currents density (15 and 30 mA/cm2) and etching times on the formation nano-sized pore array with a dimension of around few hundreds nanometric. The films were characterized by the measurement of XRD, FTIR spectroscopy and atomic force microscopy properties.
We have estimated crystallites size from X-Ray diffraction about nanoscale for porous silicon and Atomic Force microscopy confirms the nanometric size Chemical fictionalization during the electrochemical etching show on surface chemical composition of PS. The etching possesses inhomogeneous microstructures that contain a-Si clusters (Si3–Si–H) dispersed in amorphous silica matrix and (O-SiO,
C-SiO). From the FTIR analyses showed that the Si dangling bonds of the as-prepared PS layer have large amount of Hydrogen to form weak Si–H bonds. The atomic force microscopy investigation shows the rough silicon surface, with increasing etching process (current density and etching time) porous structure nucleates which leads to an increase in the depth and width (diameter) of surface pits. Consequently, the surface roughness also increases.

Effect of Heat Treatment on Changes In The Crystalline Domains In Mylar Film

N. N. Rammo; M. Abd-Sattar Mohammed; A. H. Abd Al-Razak

Engineering and Technology Journal, 2010, Volume 28, Issue 10, Pages 1997-2004

Changes in the crystalline domains caused by heat treating Mylar films
between Tg to 240 oC have been studied by Fourier Transform Infrared
spectroscopy (FTIR) and X-ray Diffraction (XRD). Prior to glass transition temperature, shrinkage in the film is insignificant, but progresses rather abruptly as melting point is approached bringing the smooth film surface to rather wrinkle.
The absorbance increase in the FTIR spectra is due to the thickened film caused by shrinking rather than the improvement in the crystalline orientation. XRD on the other hand show that heat treatment of the film near melting point only reduces the contribution of the crystalline domains in the direction [100] in favor of other direction namely rather than on the account of loosing order in favor of the amorphous regions.

Effect of Pack Cementation Coating on Hot Corrosion Resistance of Low Alloy Steel

Jawad Badr Gatea; Muna khedier Abbass

Engineering and Technology Journal, 2009, Volume 27, Issue 2, Pages 332-346

Two technique of coatings were performed by applying pack cementation
technology, the first one was aluminizing diffusion coated low alloy steel substrate
whereas the second one was single step simultaneous Co-deposition silicon- aluminum
diffusion coated low alloy steel substrate. The pack mixture used for producing both
coating systems in pack cementation process was composed of (30% Al, 2% NH4Cl and
the filler 68% Al2O3) , (30% Al , 5% Si , 2% NH4Cl and 63% Al2O3 ) respectively. The
pack temperature was 1000◦C and the diffusion time was 3 hr. XRD exhibits the phases
formed on both coated systems are Fe2Al5 , FeAl3 and FeSi . Uncoated low alloy steel
substrate and the both two coating systems were subjected to exposure environment
deposit salts mixture of (50%Na2SO4 and 50%NaCl) with weight (2mg /cm2), using
cyclic oxidation method in the experiments at temperature of 750◦C for 100hr each
cycle of 5hr. It was found that the oxidation kinetic for uncoated low alloy steel will give
evidence that the oxides formed on this alloy are non – protective. The XRD analysis
exhibited the phases are Fe2O3 , Fe3O4. It was found they followed linear rate law, and
spalling was observed. After these hot corrosion tests were undertaken, It was found that
the oxidation kinetics for both coated systems in environment consist of salt mixture
(50% NaCl +50% Na2SO4) followed parabolic law (protective oxidation behavior). XRD
exhibits the oxides formed on both coated systems are Al2O3, SiO2.