Microstructural Characterization of Silicide Coatings on Mo and TZM Alloy

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.

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.


2019 ◽  
Vol 8 (2) ◽  
pp. 36
Author(s):  
Abel. A. Barnabas ◽  
Akinlabi Oyetunji ◽  
S. O. Seidu

In this research, Scanning Electron Microscope (SEM) analysis was conducted on the produced antimony modified carbidic austempered ductile iron for agricultural implement production. Six different alloys of carbidic austempered ductile iron with varying micro quantities of antimony elements were produced. The produced alloys were heated to austenitic temperature of 910oC, held at this temperature for 1 hour, finally subjected to austempering temperatures of 300°C and 325°C for periods of 1-3 hours. The SEM in conjunction with XRD and EDS was used for the analysis. Microstructural phase morphology, phase constituents and phase compositions were viewed with SEM, XRD and EDS respectively. The results show that various phases such as spiky graphite, blocky carbides, granular carbide, pearlite and ausferrite matrix. The XRD pattern revealed some compounds such as (Fe, Cr)3C, (primary carbide), Cr6C23 (few secondary carbide), (NiFe2O4), chromite (FeCr2O4), Cr7C3 (few eutectic carbide) and Cr3Ni2. In conclusion, it was observed in terms of morphology that chunky graphite, blocky carbide and pearlite phases were present in the cast carbidic ductile iron (CDI) without antimony addition. The CDI with varying quantities of antimony additions shows spiky graphite, granular carbides and pearlite matrix. After the samples were subjected to austempering processes, all the phases were found to be intact except the pearlite phase that transformed to ausferrite phase. The antimony element in the alloys was seen to promote the formation of pearlite phase intensively. The hardness of the samples increases as the antimony addition increases from 0.096wt.% to 0.288wt.% owing to the increase in pearlite phase, while the impact toughness reaches relatively high level, when 0.288wt.% antimony was added, probably due to the refinement of graphite nodules. All the results obtained showed that appropriate content of antimony addition plays an important role in increasing the nucleation rate of graphite nodules, and also lead to improvement in carbide formation thereby providing good balance between wear and impact properties.


2012 ◽  
Vol 616-618 ◽  
pp. 1732-1735 ◽  
Author(s):  
Xi Hai Shen ◽  
Yu Gang Zheng ◽  
Liang Chang ◽  
Jin Jia Guo ◽  
Song Bin Ye ◽  
...  

Aiming at the glass-to-metal seals serving in the Solar Thermal Power (STP), glass-to-metal vacuum brazed joints were studied. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed to examine the microstructure and element contents of interface seam on the glass-to-metal vacuum brazed joints. Also, the compositional concentration of the interface seam was measured by using energy dispersive spectroscopy (EDS).


2014 ◽  
Vol 87 ◽  
pp. 79-84
Author(s):  
Francesca Mazzanti ◽  
Giuseppe Magnani ◽  
Selene Grilli ◽  
Aldo Brillante ◽  
Tommaso Salzillo ◽  
...  

SOREME project (LIFE 11 ENV/IT/109) is aimed at synthesizing an innovative sorbent based on activated carbon obtained from the carbonization of waste tires. Microstructural characterization was mainly performed in order to define crystallinity, morphology and porosity of the activated carbon powders obtained in different conditions. In particular, XRD analysis always revealed a partially crystalline structure with different crystallite size of the nanographitic structure. The disorder of these structures was determined by Raman spectroscopy. This evaluation was made on the basis of the ratio of the integrated area of the D and G bands typical of the graphitic structure. Finally, SEM was used to put in evidence the mesopores and macropores.


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.


2014 ◽  
Vol 805 ◽  
pp. 116-121 ◽  
Author(s):  
Greyce Yane Honorato Sampaio ◽  
Ana C.B.M. Fook ◽  
Thiago Bizerra Fideles ◽  
M.E.R.R.M. Cavalcanti ◽  
Marcus Vinícius Lia Fook

Currently researchers has pointed chitosan as one of the viable alternatives for application as scaffolds in tissue regeneration, mainly due to its availability, biocompatibility, biodegradability and ability to chemical modifications, among them, the crosslinking. With the growing number of investigations of crosslinking agents from natural sources and its applicability, this work focuses on the development and microstructural characterization of chitosan scaffolds and chitosan crosslinked with genipina using the technique of freeze drying. Solutions were prepared with chitosan concentration of 2% (w / t), and genipin 0.15% (w / t) and 0.3% (w / t). These were frozen at-20 ° C and ≈ 196 ° C, and lyophilized. The effect of different concentrations of genipin and freezing rates of the solutions in the porous architecture of the scaffolds were evaluated by Scanning Electron Microscopy (SEM), Optical Digital Microscopy 2D and 3D (OM) and testing the Degree of Swelling (DS). The SEM analysis revealed the formation of a three dimensional structure with pores and / or channels interconnected, influenced by the freezing rate and addition of crosslinking agent, these variables also influence the absorption capacity of the scaffolds. It was observed by OM, the effectiveness of the crosslinking with genipin, through points of fluorescence presented.


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.


2014 ◽  
Vol 1015 ◽  
pp. 688-691 ◽  
Author(s):  
Feng Wang ◽  
Qiang Zhang ◽  
Bai Qing Xiong ◽  
Yong An Zhang ◽  
Hong Wei Liu ◽  
...  

An innovative spray deposition technique has been applied to produce in situ TiB2/Zn-30Al-1Cu composites. The microstructures of the spray-deposited composite were studied using scanning electron microscopy, transmission electron microscope and X-ray diffraction. The results have shown that the TiB2particulates are formed in the microstructure. It was found that the TiB2particles were distributed in Zn-30Al-1Cu matrix uniformly, and the TiB2particles are about 2μm in size.


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.


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