Characterization of TiC/Ti5Si3 In Situ Synthesis Composite Materials on Ti-5Al-2.5Sn by Argon Tungsten-Arc Welding Deposition

2012 ◽  
Vol 182-183 ◽  
pp. 180-184 ◽  
Author(s):  
Wen Qing Yan ◽  
Le Dai ◽  
Chi Bin Gui

TiC/Ti5Si3composite materials on Ti-5Al-2.5Sn were in-situ synthesized by argon tungsten-arc welding (GTAW) deposition from powder compacts with the molar ratio of Ti:Si:C=3:1:2. X-ray diffraction (XRD) techniques and scanning electron microscope (SEM) were employed to characterize the microstructure of the composites. The effects of depositing times on the surface microstructure of the tracks deposited were studied. From the products synthesized in this work, the content of TiC/Ti5Si3in-situ composites on the surface of the tracks differed from each other by depositing one, two, three, and four times, respectively. The minimum impurities were obtained and the distribution of TiC/Ti5Si3. In-situ composites were most homogeneous in the track surface by depositing three times.

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Chakradhar Sridhar ◽  
Nagesh Gunvanthrao Yernale ◽  
M. V. N. Ambika Prasad

The present study deals with the synthesis and characterization of nanocrystalline vanadium pentoxide (V2O5) nanoparticles and their antibacterial and antifungal activity onStaphylococcus aureus and Aspergillus niger, respectively, by agar diffusion method. The metal oxide has been synthesized by employing the sol-gel method, polyaniline (PANI) has been synthesized by chemical oxidation, and PANI/V2O5composites have been synthesized byin situpolymerization method with different ratios (10, 20, 30, 40, and 50 weight%) of V2O5in PANI. The newly prepared composites were characterized by FTIR and powder X-ray diffraction (P-XRD) techniques and are found to be formed of PANI/V2O5nanocomposites, and also the compounds showed moderate antibacterial and antifungal activity.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
G. A. Bertero ◽  
W.H. Hofmeister ◽  
N.D. Evans ◽  
J.E. Wittig ◽  
R.J. Bayuzick

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


2010 ◽  
Vol 663-665 ◽  
pp. 542-545 ◽  
Author(s):  
Bing Jie Zhu ◽  
Xin Wei Wang ◽  
Mei Fang Zhu ◽  
Qing Hong Zhang ◽  
Yao Gang Li ◽  
...  

The PANI/ITO conducting nanocomposites have been synthesized by in-situ polymerization. The obtained nanocomposites were characterized by X-ray diffraction pattern, scanning electron microscopy and Fourier transform infrared. Electrical conductivity measurements on the samples pressed into pellets showed that the maximum conductivity attained 2.0 ± 0.05 S/cm for PANI/ITO nanocomposites, at ITO doping concentration of 10 wt%. The results of the present work may provide a simple, rapid and efficient approach for preparing PANI/ITO nanocomposites.


2000 ◽  
Vol 15 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
Jan Schroers ◽  
Konrad Samwer ◽  
Frigyes Szuecs ◽  
William L. Johnson

The reaction of the bulk glass forming alloy Zr41Ti14Cu12Ni10Be23 (Vit 1) with W, Ta, Mo, AlN, Al2O3, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials.


2009 ◽  
Vol 24 (8) ◽  
pp. 2541-2546 ◽  
Author(s):  
Eisuke Yokoyama ◽  
Hironobu Sakata ◽  
Moriaki Wakaki

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.


2002 ◽  
Vol 57 (6) ◽  
pp. 621-624 ◽  
Author(s):  
Wolfgang Fraenk ◽  
Heinrich Nöth ◽  
Thomas M. Klapötke ◽  
Max Suter

AbstractTetraphenylphosphonium tetraazidoborate, [P(C6H5)4][B(N3)4], was obtained from B(N3)3 - in situ prepared from BH3 · O(C2H5)2 and HN3 - and [P(C6H5)4][N3]. Recrystallization from an acetonitrile / hexane mixture yielded colorless crystals in 60% yield. The molecular structurewas determined by single crystal X-ray diffraction and the [B(N3)4]- anionwas shown to possess S4 symmetry.


2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Marwa Ammar ◽  
Walid Oueslati

This work reports characterization of the possible effects that might distress the hydration properties of Mg-exchanged low-charge montmorillonite (SWy-2) when it undergoes external environmental solicitation. This perturbation was created by an alteration of relative humidity rates (i.e., RH%) over two hydration-dehydration cycles with different sequence orientations. Structural characterization is mainly based on the X-ray diffraction (XRD) profile-modeling approach achieved by comparing the “in situ” obtained experimental 00l reflections with other ones calculated from theoretical models. This method allows assessing the evolution of the interlayer water retention mechanism and the progress of diverse hydration state’s contributions versus external strain. Obtained results prove that the hydration behavior of the studied materials is strongly dependent on the RH sequence orientation which varied over cycles. The interlayer organization of Mg-exchanged montmorillonite (i.e., SWy-2-Mg) is characterized by a heterogeneous hydration behavior, which is systematically observed at different stages of both cycles. By comparing the interlayer water process evolution of Mg-exchanged montmorillonite with the observed SWy-2-Ni sample hydration behaviors, a same hysteresis thickness characterized by obvious fluctuations of interlayer water molecule abundances is observed. Nevertheless, in the case of Hg and Ba-saturated montmorillonite, the retention water process versus the applied cycles was steadier comparing with Mg ions.


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