scholarly journals Preparation and Tribocorrosion Performance of Different Si-Doped TiSiN-Ag Coatings on Different Substrates in Seawater

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 459
Author(s):  
Ke Cai ◽  
Bailing Jiang ◽  
Jing Zhang ◽  
Xiaolei Su

TiSiN-Ag composite coatings with different Si doping contents were prepared by multi-arc ion plating technology on 316L, TC4, and H65 copper substrates, respectively. The microstructure of the prepared coatings was characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy, respectively. The mechanical properties, electrochemical properties, and tribological properties were characterized by a micro-hardness tester, electrochemical workstation, scratch tester, and friction and wear tester, respectively. Results showed that the coatings with 8 wt.% Si doping content had a smaller average grain size, denser structure, excellent mechanical properties, and better anti-tribocorrosion performance than those with 5 wt.% Si doping content. The coating on the TC4 substrate with 8 wt.% Si doping content presented the best combination of properties and is a candidate for an anti-tribocorrosion material in seawater.

2012 ◽  
Vol 236-237 ◽  
pp. 113-117
Author(s):  
Song Wang ◽  
Ming Xie

W-26Re alloy was fabricated by spark plasma sintering (SPS) technology. The phases, microstructures and mechanical properties of the alloy were investigated by X-ray diffraction, optical light microscope, scanning electron microscope, energy dispersion spectroscope, digital display micro-hardness tester and tensile test. Results show that, using SPS technique can prepare W-26Re alloy with high density, fine grain and excellent mechanical properties. The relative density of W-26Re alloy was 96.2%. The main phases in the alloy were determined by the amount of (W) solid solution and the intermetallic  phases. The micro-hardness was 729HV, the ultimate tensile strength was 1680MPa, yield tensile strength was 1143MPa and elongation of alloy was 8.7%.


2013 ◽  
Vol 27 (19) ◽  
pp. 1341011
Author(s):  
YING JU ◽  
YUXIN WANG ◽  
YI WEN ◽  
WEI GAO

This investigation described the development of a technique to produce Au – Co nanostructured composite coatings with improved hardness. Pulse power has been used with the traditional Au electroplating solution to synthesize multilayer nanocomposite coatings. The phase structure was analyzed by X-ray diffraction. Mechanical properties were investigated using nanoindentation. The results indicate that the hardness was increased to 3.15 ± 0.05 GPa , compared to 2.70 ± 0.07 GPa of that produced by the direct current Au coatings. The hardening mechanisms have also been discussed.


2012 ◽  
Vol 445 ◽  
pp. 982-987 ◽  
Author(s):  
Oguzhan Gunduz ◽  
Zeeshan Ahmad ◽  
S. Salman ◽  
Ahmet Talat Inan ◽  
Nazmi Ekren ◽  
...  

The use of bovine hydroxyapatite (BHA) provides an alternative approach in bioceramics based on natural resources, time and cost efficiency. In this study, composites of calcinated bovine derived BHA were utilized. These were doped with known quantities of boron based bioglass (5 and 10 wt. %) and a range of composites were prepared at selected sintering temperatures (1000-1300 °C). The resulting structures were tested for several mechanical properties (porosity, compression and microhardness). Micro-structural analysis (electron microscopy and x-ray diffraction) was also performed on these samples, and these findings were correlated with results obtained from mechanical tests. The results indicate that there is a positive correlation between compression strength and sintering temperature and the optimal properties are obtained at a temperature of 1200°C and a boron oxide bioglass doping content of 5 wt. %.


2017 ◽  
Vol 866 ◽  
pp. 282-286 ◽  
Author(s):  
Chatchai Kruea-In ◽  
Suchittra Inthong ◽  
Wilaiwan Leenakul

In this research, The effects of NiO nanoparticles on the physical and mechanical properties of Bi0.5(Na0.81,K0.19)0.5TiO3 (BNKT) were investigated. The ceramics were synthesized by solid state reaction technique. The powder of BNKT was calcined at 850 °C for 4 h. The ceramics of BNKT/x NiO vol.% ( i.e. x= 0.0, 1.0, 2.0 and 3.0) were sintered at 1000-1150 °C for 2 h for optimize condition. Densification, phase formation, microstructure and micro hardness of samples were characterized via Archimedes method, X-ray diffraction techniques (XRD), scanning electron microscope (SEM) and Vickers micro hardness tester. The X-ray diffraction analysis of the ceramics suggests that all samples exhibited a perovskite structure. Densification of samples tended to increase with increasing amount of NiO content with minimun at 1.0 vol.% NiO additive. The NiO additive influenced densification as well as the mechanical properties of the samples. The results of this research suggest that NiO nanoparticles have influence on physical and mechanical properties of BNKT ceramics.


2018 ◽  
Vol 12 (3) ◽  
pp. 268-276 ◽  
Author(s):  
Zeljko Radovanovic ◽  
Ðordje Veljovic ◽  
Lidija Radovanovic ◽  
Ilmars Zalite ◽  
Eriks Palcevskis ◽  
...  

Green hydroxyapatite ceramics were obtained by cold uniaxial and isostatic pressing of hydrothermally synthesized powders, pure hydroxyapatite and hydroxyapatite doped with Ag+, Cu2+ and Zn2+ ions. The ceramics were conventionally and microwave sintered and analyzed by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction analysis, and energy-dispersive X-ray spectroscopy. The effect of doping on the mechanical properties of the obtained hydroxyapatite/tricalcium phosphate ceramics was examined by comparing their average grain size, porosity and values of the hardness and fracture toughness. The results showed that doping with Cu2+ ions caused the lowest porosity of the ceramics and the highest values of hardness and fracture toughness. The ceramics obtained from hydroxyapatite doped with Ag+ and Zn2+ ions exhibited worse mechanical properties due to the higher porosity even in the case of microwave sintering, which provide denser ceramics than conventional sintering.


2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.


2014 ◽  
Vol 900 ◽  
pp. 172-176 ◽  
Author(s):  
Ji Mei Niu ◽  
Zhi Gang Zheng

The Fe3O4 magnetic nanoparticles obtained by the aqueous coprecipitation method are characterized systematically using scanning electron microscope, X-ray diffraction and vibrating sample magnetometer. These magnetic nanoparticles are spheric, dispersive, and have average grain size of 50 nm. The size and magnetic properties of Fe3O4 nanoparticles can be tuned by the reaction temperature. All samples exhibit high saturation magnetization (Ms=53.4 emu·g-1) and superparamagnetic behavior with a block temperature (TB) of 215K. These properties make such Fe3O4 magnetic nanoparticles worthy candidates for the magnetic carriers of targeted-drug or gene therapy in future.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 440
Author(s):  
Fabiana Pereira da Costa ◽  
Jucielle Veras Fernandes ◽  
Luiz Ronaldo Lisboa de Melo ◽  
Alisson Mendes Rodrigues ◽  
Romualdo Rodrigues Menezes ◽  
...  

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1563
Author(s):  
Sofia Marquez-Bravo ◽  
Ingo Doench ◽  
Pamela Molina ◽  
Flor Estefany Bentley ◽  
Arnaud Kamdem Tamo ◽  
...  

Extremely high mechanical performance spun bionanocomposite fibers of chitosan (CHI), and cellulose nanofibers (CNFs) were successfully achieved by gel spinning of CHI aqueous viscous formulations filled with CNFs. The microstructural characterization of the fibers by X-ray diffraction revealed the crystallization of the CHI polymer chains into anhydrous chitosan allomorph. The spinning process combining acidic–basic–neutralization–stretching–drying steps allowed obtaining CHI/CNF composite fibers of high crystallinity, with enhanced effect at incorporating the CNFs. Chitosan crystallization seems to be promoted by the presence of cellulose nanofibers, serving as nucleation sites for the growing of CHI crystals. Moreover, the preferential orientation of both CNFs and CHI crystals along the spun fiber direction was revealed in the two-dimensional X-ray diffraction patterns. By increasing the CNF amount up to the optimum concentration of 0.4 wt % in the viscous CHI/CNF collodion, Young’s modulus of the spun fibers significantly increased up to 8 GPa. Similarly, the stress at break and the yield stress drastically increased from 115 to 163 MPa, and from 67 to 119 MPa, respectively, by adding only 0.4 wt % of CNFs into a collodion solution containing 4 wt % of chitosan. The toughness of the CHI-based fibers thereby increased from 5 to 9 MJ.m−3. For higher CNFs contents like 0.5 wt %, the high mechanical performance of the CHI/CNF composite fibers was still observed, but with a slight worsening of the mechanical parameters, which may be related to a minor disruption of the CHI matrix hydrogel network constituting the collodion and gel fiber, as precursor state for the dry fiber formation. Finally, the rheological behavior observed for the different CHI/CNF viscous collodions and the obtained structural, thermal and mechanical properties results revealed an optimum matrix/filler compatibility and interface when adding 0.4 wt % of nanofibrillated cellulose (CNF) into 4 wt % CHI formulations, yielding functional bionanocomposite fibers of outstanding mechanical properties.


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