Laser Remelting of Silicide Coatings on Mo and TZM Alloy

2015 ◽  
Vol 226 ◽  
pp. 121-126 ◽  
Author(s):  
Grzegorz Moskal ◽  
Andrzej Grabowski ◽  
Aleksander Lisiecki

Characterization of top surface and microstructure of silicide coatings obtained during diffusion process of pack cementation type and laser remelting treatments was showed in this article. The basic materials were pure Mo sheet and TZM molybdenum alloy. The coatings were deposited in powder process and glazed by different types of lasers. In first step the phase’s compositions of coatings was described by XRD analysis in initial condition and after remelting process. The morphology of the coatings top surface was described as well. All types of coatings were characterized by network of cracks on top surface of the coatings. Laser treatment of the silicide top surface changed morphology of the top surface, especially their cracks network. LM and SEM analysis revealed that internal coatings morphology was very similar in all cases.

2014 ◽  
Vol 1036 ◽  
pp. 164-167 ◽  
Author(s):  
Grzegorz Moskal ◽  
Lucjan Swadźba ◽  
Wacław Supernak ◽  
Marta Mikuśkiewicz ◽  
Adrian Mościcki ◽  
...  

Characterization of microstructure of silicide coatings obtained during diffusion process of pack cementation type was showed in this article. The basic materials were pure Mo sheet and TZM molybdenum alloys as well. The coatings were deposited in out of pack process with three different times of exposure. The temperature of deposition process was constant. In first step the phases compositions of coatings was described by XRD analysis. In each cases the MoSi2 phase was obtained on top surface of the coatings. The morphology of the coatings was very similar as well. All types of coatings were characterized by network of cracks on top surface of the coatings. There was no influence of depositions time on phases constituent and coatings topography. LM and SEM analysis revealed that internal coatings morphology was very similar in all cases. Basic differences was related to the thickness of coatings. All coatings were good quality without deep cracks. Microstructure was a columnar-like type without pores and voids.


2013 ◽  
Vol 587 ◽  
pp. 239-244 ◽  
Author(s):  
Kunjalukkal Padmanabhan Sanosh ◽  
Francesca Gervaso ◽  
Alessandro Sannino ◽  
Antonio Licciulli

In the present work Collagen/Hydroxyapatite microsphere (Col/mHA) scaffold with a multiscale porosity was prepared. Col/mHA composite scaffold was prepared by freeze-drying/dehydrothermal crosslinking method. The HA microspheres (mHA) were obtained by spray drying of nanohydroxyapatite slurry prepared by precipitation technique. XRD analysis revealed that the microspheres were composed only of pure HA phase and EDS analysis revealed that Ca/P ratio was 1.69. The obtained microspheres had an average diameter 6 microns, specific surface area of 40 m2/g by BET analysis and BJH analysis shows meso porous structure having an average pore diameter 16nm. SEM analysis shows that the obtained Col/mHA scaffold had a macro porosity ranging from micron to 200 microns with meso porous mHA embedded in the collagen matrix.


Author(s):  
Priscila Richa ◽  
Roberto Costa Lima ◽  
Ana Paula Santiago de Falco ◽  
Ana Paula da Silva ◽  
Elvia Leal ◽  
...  

Radar-absorbing materials (RAMs) have been used in military applications for several decades to reduce radar detection of vessels and aircrafts. In the present work, the performance of Ni0.35Zn0.35Cu0.3Fe2O4 ferrite as a RAM is investigated. The ferrite was firstly synthesized by combustion reaction and then calcinated at 1200 °C for 1 h. Composites were prepared with 80:20, 70:30 and 60:40 concentrations in weight of ferrite:polychloroprene. The X-ray diffraction (XRD) analysis showed a single phase ferrite formation and the scanning electron microscopy (SEM) analysis of the composites showed a good dispersion of the ferrite in the polychloroprene matrix. The electromagnetic (EM) characterization of the composites revealed that the EM attenuation is mainly attributed to magnetic losses observed in the material. The 80:20 composite achieved the best performance and presented a reflectivity of -26.7 dB at 10.2 GHz.


2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Maria Ulfah ◽  
Sri Aprilia ◽  
Fauzi M. Djuned

<p>Utilization of wood powder is one of the alternative in waste wood prevention which has not been optimally utilized. Utilization of bionanofiller based on wood waste such as wood powder can also reduce dependence on raw materials such as silica, clay, bentonite, zeolite which diminished its existence. The sample used in this study is Meranti wood powder which is then prepared and characterized. The characterization of bionanofiller waste of Meranti wood powder is done by analyzing particle density, XRD, SEM, and FTIR. Particle density analysis showed Meranti wood powder having density of 0,044 gr/cm . XRD analysis shows that the maximum peak at an angle of 2θ = 22,2o 3 indicates the presence of carbon phase. The results of SEM analysis of Meranti wood powder are suitable for use as fillers because they are 1 μm in size. The result of functional group analysis shows the presence of functional groups -OH, -CH3, -CH2, C = C, C-H and C-O.</p>


2015 ◽  
Vol 51 (3) ◽  
pp. 663-671 ◽  
Author(s):  
Vikas Bhandari ◽  
Amelia Avachat

The purpose of present study was aimed at developing self emulsifying drug delivery system in liquid and then in pellet form that would result in improved solubility, dissolution and permeability of the poorly water soluble drug carvedilol. Pellets were prepared using extrusion-spheronization technique incorporating liquid SEDDS (carvedilol, capmul MCM EP, cremophore EL, tween 20, propylene glycol), adsorbents ( and crospovidone), microcrystalline cellulose and binder (povidone K-30). Ternary phase diagram was constructed to identify different oil-surfactant-cosurfactant mixtures according to the proportion of each point in it. The optimal CAR-SEDDS pellets showed a quicker redispersion with a droplet size of the reconstituted microemulsion being 160.47 nm, which was almost unchanged after solidification. SEM analysis confirmed good spherical appearance of solid pellets; DSC and XRD analysis confirmed that there was no crystalline carvedilol in the pellets. Pellets were then capable of transferring lipophilic compounds into the aqueous phase and significantly enhancing its release with respect to pure drug.


2019 ◽  
Vol 280 ◽  
pp. 04003
Author(s):  
Agus Mirwan ◽  
Meilana Dharma Putra ◽  
Riani Ayu Lestari

The existence of peat clay is scattered in many parts of the world with the huge amount. The high compound of minerals in the peat clay can be potentially used as adsorbent and catalyst. This research aims to study the composition of peat clay and functional group of the compound in the peat clay. The characterization of x-ray fluorescence (XRF), fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and scanning electron microscope-energy dispersive x-ray (SEM- EDX) were assigned to compare the sample before and after calcination process at 700 oC 120 min. FTIR analysis showed the presence of quartz, kaolinite, hematite, illite in peat clay. The results of XRF analysis showed that chemical composition of peat clay was dominantly in the form of silica oxide (18%), aluminum oxide (7%), and iron oxide (15%). The amount of compounds was observed to increase to be 32%, 18% and 11%, respectively after calcinations. XRD analysis confirmed the presence of this mineral in the peat clay. SEM analysis showed flake structure of peat clay with EDX which indicated composition of the dominant element namely the presence of Al, Si, and Fe before and after calcination. This high amount of minerals in peat clay led to potential source to be utilized as adsorbent for removing the pollutant or as and catalyst for chemical process.


2020 ◽  
Vol 9 (10) ◽  
pp. e7919109123
Author(s):  
Fabíola Stahlke Prado ◽  
Tânia Cristina Simões ◽  
Alejandra Hortencia Miranda González

The aim of the investigation was to synthesize 3 mol% yttria-stabilized zirconia (3Y-TZP) powders via polymeric precursor method (PPM). The precursor solution was preheated at 350ºC for 3h, subsequently thermally treated at 500ºC for 3h and 800ºC for 6h. The obtained materials were analyzed by Thermogravimetry-Derivative Thermogravimetry (TG/DTG), Differential Thermal Analysis (DTA), powder X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Two commercially available Y-TZP ceramic systems were chosen for comparison. XRD analysis of the synthesized 3Y-TZP powders revealed the crystallization of the tetragonal phase, while both commercial systems showed the coexistence of the monoclinic and tetragonal phases. SEM analysis showed that the powders thermally treated at 800°C consist of agglomerated spherical nanoparticles. Morphology of commercial systems also revealed nanosized spherical particles. Results revealed that the PPM led to ceramics with structural and morphological properties comparable to commercially available reinforced dental ceramics.


2021 ◽  
Vol 9 (2) ◽  
pp. 22-25
Author(s):  
Shawbo A. Abubaker ◽  
Faten A. Chaqmaqchee ◽  
Akram H. Taha

In this study, different types of polymers in postconsumer plastics with pure plastics have been studied. Highdensity polyethylene (HDPE1 and HDPE2), polyvinyl chloride (PVC3 and PVC4), polyethylene terephthalate (PET5 and PET6), and polypropylenes (PP7 and PP8) were compared using X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. XRF has shown the spectral in K-lines of polymer materials present in plastics waste. The peak intensity and degree of crystallinity of commercial polymers are varied using XRD analysis. The intensity not attributable to the crystalline peaks may be regarded as the amorphous scattering and used as a template in analyzing the diffraction pattern of the samples. The XRD analysis helps to provide characteristic spectral lines whose intensities vary with the type of each constituent polymer. The combined usage of XRD and XRF techniques yielded very useful and effective results for a commercial plastic management.


2021 ◽  
Vol 2129 (1) ◽  
pp. 012009
Author(s):  
R Nedjai ◽  
N A Kabbashi ◽  
M Z Alam ◽  
M F R Al-Khatib

Abstract Chemical agents have a good influence on the formation of activated carbons, surface characteristic, and its adsorption properties. In this study, the effect of activating agents (ZnCl2, KOH, and H3PO4) on baobab fruit shell (BFS) were evaluated. The characteristics of the baobab fruit shell based activated carbon (BF-ACs) were evaluated through the yield and iodine number. BF-ACs were also characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and nitrogen (N2) adsorption. SEM analysis illustrates those porous structures formed on the surface of BF-ACs were with different sizes. The XRD analysis show that the main structures of BF-ACs are amorphous. FT-IR data demonstrates the presence of different surface groups on the produced BF-ACs. Among activating agent, the KOH was observed to the most appropriate for the production of activated carbon with a large surface area (1029.44 m2/g) from baobab fruit shell.


2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Syed Md. Ihsanul Karim ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Md. Maksud Helali

This work examines how vapor-deposited coating of DLC (partially diamond) on stainless steel 304 substrate is affected by the sound vibration. For this, a specially designed chemical vapor deposition (thermal CVD and hot filament) apparatus having facility of generating sound vibration at different frequency is fabricated. A coating of DLC (partially diamond) has been deposited on the substrate, and the characterization of the coating has been done by SEM, EDX, and XRD. The coating of carbon is identified by EDX, and the allotropic forms of graphite and diamond peaks of carbon are found by XRD analysis. By SEM analysis, it is found that the microstructures of deposited coatings are more compact and smoother under vibration than those in absence of vibration. The experiments were conducted under different ranges of vibration including sonic and ultrasonic range. Studies have shown that the growth rate of deposited coating on a unit area is higher under vibration than that in absence of vibration. It is found that deposition rate varies with the distance between substrate and activation heater and frequency of vibration. The deposition rate does not vary significantly with the change of frequency in the sonic range. The amount of deposition under ultrasonic vibration increases significantly with the frequency of vibration upto 5-6 mm distance between substrate and activation heater. Within this distance, the difference of deposition rate under vibration and without vibration conditions increases almost linearly with the increase of frequency of vibration. Beyond this distance, the effect of frequency on deposition rate becomes almost constant. In addition, the higher the distance, the less is the effectiveness of frequency of vibration on the deposition rate in that range. The deposition rate increases due to the extra vibration of sound added to the system which may enhance the activation energy by increasing its kinetic energy. The experimental results are compared with those available in the literature, and physical explanations are provided.


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