scholarly journals In Situ Evaluation of the Influence of Interstitial Oxygen on the Elastic Modulus of La2NiO4

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1889
Author(s):  
Yuta Kimura ◽  
Takashi Nakamura ◽  
Koji Amezawa ◽  
Keiji Yashiro ◽  
Tatsuya Kawada
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Oxygen Concentration ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Young's Modulus ◽  
Resonance Method ◽  
Lattice Defects ◽  
Interstitial Oxygen

Lattice defects significantly affect the mechanical properties of crystalline metal oxides. The materials for the components of solid oxide fuel cells (SOFCs) are no exception, and hence understanding of the interplay between lattice defects and the mechanical properties of components is important to ensure the mechanical stability of SOFCs. Herein, we performed an in situ evaluation of the temperature and P(O2) dependence of the elastic moduli of La2NiO4 (LN214), a candidate for the cathode material of SOFCs, using the resonance method to understand the influence of interstitial oxygen on its elastic properties. Above 873 K, both the Young’s and shear moduli of LN214 slightly decreased with increasing P(O2), suggesting that these elastic moduli are correlated with interstitial oxygen concentration and decreased with increasing interstitial oxygen. We analyzed the influence of interstitial oxygen on the Young’s modulus of LN214, based on numerically obtained lattice energy. The P(O2) dependence of the Young’s modulus of LN214 was found to be essentially explained by variation in the c-lattice constant, which was triggered by variation in interstitial oxygen concentration. These findings may contribute to a better understanding of the relationship between lattice defects and mechanical properties, and to the improvement of the mechanical stability of SOFCs.

Mechanical Properties of Pyrolytic "SiOCN" Thin Coatings

1993 ◽  
Vol 308 ◽  
Author(s):  
Sandrine Bec ◽  
André Tonck ◽  
Jean-Luc Loubet
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Ceramic Coatings ◽  
Optical Observation ◽  
Thin Coatings ◽  
Polymer Precursors ◽  
Polymeric State

ABSTRACTPyrolysis of polymer precursors (polysilazane) is a technologically and economically interesting way to produce thin ceramic coatings. However, many cracks appear and decohesion occurs during pyrolysis when the ceramic coatings (SiOCN) are thicker than 0.5 micrometers. In order to understand these cracking phenomena, the coatings are mechanically characterized by nanoindentation at different stages of the pyrolysis heat treatment.During pyrolysis, the cracking temperature is detected by in-situ optical observation. The thickness of the coatings varies during pyrolysis from 3 micrometers at the polymeric state to 1 micrometer at the ceramic state. The coatings' properties, hardness and Young's modulus are evaluated after heat treatment, taking into account the substrate's influence. A large variation of these properties occurs at the cracking temperature. Both the hardness and the Young's modulus are multiplied by a factor of 10. By analysing these results, we show that cracking is correlated with the evolution of the coatings' mechanical properties during the transformation.

Mechanical Properties Of Cu-Based Composites with in Situ Formed Ultrafine Filaments

1981 ◽  
Vol 12 ◽  
Author(s):  
J. Bevk ◽  
W. A. Sunder ◽  
G. Dublon ◽  
David E. Cohen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Young’S Modulus ◽  
Size Dependence ◽  
Young's Modulus ◽  
Plastic Properties ◽  
Young’S Moduli ◽  
Lattice Softening

ABSTRACTElastic and plastic properties of in situ Cu-based composites with Nb, V, and Fe filaments are reviewed. The evidence is presented for a pronounced size dependence of both the ultimate tensile strength and the Young's moduli. In composites with the smallest filaments (d∼50–200Å) and filament densities as high as 1010/cm2 dislocation density reaches values of 1013 cm/cm3. The yield stress of these samples increases dramatically over the predictions based on the “rule of mixtures” and their ultimate tensile strength approaches the estimated theoretical strength of the material (∼2.7GPa). The observed decrease of Young's modulus as a function of inverse wire diameter in the as-drawn composites is attributed to lattice softening due to high density of extended lattice defects. Upon annealing, Young's modulus increases by as much as 100% and exceeds the maximum values calculated from bulk elastic constants. Possible mechanisms leading to modulus enhancement and to related changes in magnetic and superconducting behavior of in situ composites are discussed.

Microstructure Formation Mechanism of (Al2O3+TiB2+Al3Ti)/Al Composites Fabricated by Reactive Hot Pressing

2007 ◽  
Vol 353-358 ◽  
pp. 1439-1442 ◽  
Author(s):  
Gui Song Wang ◽  
Lin Geng
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Formation Mechanism ◽  
Hot Pressing ◽  
Young's Modulus ◽  
Microstructure Formation ◽  
Sem And Tem ◽  
Reactive Hot Pressing ◽  
Tib2 Particles

The two (Al2O3+TiB2+Al3Ti)/Al composites were fabricated from Al-B2O3-TiO2 and Al-B-TiO2 raw powders by reactive hot pressing, respectively. The microstructure of in situ two composites was analyzed by OM, SEM and TEM. The results showed that coarse Al3Ti blocks with several tens of micrometers size were formed during hot pressing. The equiaxed Al2O3 particulates and hexagonal TiB2 particulates with finer sizes were formed in the composites simultaneously. The microstructure formation mechanism of (Al2O3+TiB2+Al3Ti)/Al composites were discussed. The results showed that Al2O3 reinforcements were formed on the surface of TiO2 or B2O3 powder and TiB2 particles were formed on B or B2O3 powders. The formation of coarse Al3Ti block is result from continuous diffusion of Ti in liquid Al during reactive hot pressing. In addition, there are fine Al3Ti precipitates exist in the composite fabricated from Al-B-TiO2 powders. This contributes to the improved mechanical properties in terms of yield and ultimate stresses and Young’s modulus of the composite.

Properties of Cu-TiB2 Composites Fabricated by In-Situ Liquid Melt Mixing Process

2006 ◽  
Vol 15-17 ◽  
pp. 215-219 ◽  
Author(s):  
J.H Yun ◽  
J.H. Kim ◽  
J.S. Park ◽  
Young Do Park ◽  
Yong Ho Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Mixing Process ◽  
Melt Mixing ◽  
Maximum Value ◽  
S Model ◽  
Good Agreement

A Cu-TiB2 composite was successfully fabricated by in-situ liquid mixing process, and its microstructure, mechanical properties as well as electrical conductivity were evaluated. For Cu-2vol.%TiB2 composite, the hardness was as high as 5GPa and the Young’s modulus was 130GPa. And hardness and Young’s modulus of Cu-6vol.%TiB2 composite was 5.6Gpa and 138GPa, respectively. With the increase of the TiB2 content, hardness and Young’s modulus of Cu-10vol.%TiB2 composite were 20 and 12%, respectively, which was higher than that of Cu-2vol.%TiB2 composite. Young’s modulus of the Cu-TiB2 composite in this paper was in good agreement with the prediction by Hashin-Shtrikman (H-S) model. Furthermore, the electrical conductivity of the Cu-TiB2 composite showed its maximum value of about 78%IACS and decreased with the increase of the TiB2.

Synthesis of Biodegradable β-TCP/PLGA Composites Using Microwave Energy

2006 ◽  
Vol 510-511 ◽  
pp. 758-761 ◽  
Author(s):  
Hyeong Ho Jin ◽  
Sang Ho Min ◽  
Kyu Hong Hwang ◽  
Ik Min Park ◽  
Hong Chae Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Young’S Modulus ◽  
Tricalcium Phosphate ◽  
Bending Strength ◽  
In Situ Polymerization ◽  
Young's Modulus ◽  
Microwave Energy ◽  
Microstructure And Mechanical Properties

Biodegradable β-tricalcium phosphate (β-TCP)/poly (lactide-co-glycolide) (PLGA) composites were synthesized by in situ polymerization with microwave energy. The influence of the β-TCP content in β-TCP/PLGA composites on the molecular weight, crystallinity, microstructure, and mechanical properties was investigated. As the molecular weight of composites decreased, the β-TCP content increased up to 10 wt%, while further raising of the β-TCP content above 10%, the molecular weight increased with increasing β-TCP content. This behavior may be ascribed to the superheating effect or nonthermal effect induced by microwave energy. It was found that the bending strength and Young’s modulus of the β-TCP/PLGA composites were proportional to the molecular weight of PLGA. The bending strength of the β-TCP/PLGA composites ranged from 18 to 38 MPa, while Young’s modulus was in the range from 2 to 6 GPa.

scholarly journals Determination of Young’s modulus of Sb2S3 nanowires by in situ resonance and bending methods

2016 ◽  
Vol 7 ◽  
pp. 278-283 ◽  
Author(s):  
Liga Jasulaneca ◽  
Raimonds Meija ◽  
Alexander I Livshits ◽  
Juris Prikulis ◽  
Subhajit Biswas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Cross Section ◽  
Young's Modulus ◽  
Cross Sectional ◽  
Bending Tests ◽  
Young’S Moduli ◽  
Increasing Trend

In this study we address the mechanical properties of Sb2S3 nanowires and determine their Young’s modulus using in situ electric-field-induced mechanical resonance and static bending tests on individual Sb2S3 nanowires with cross-sectional areas ranging from 1.1·104 nm2 to 7.8·104 nm2. Mutually orthogonal resonances are observed and their origin explained by asymmetric cross section of nanowires. The results obtained from the two methods are consistent and show that nanowires exhibit Young’s moduli comparable to the value for macroscopic material. An increasing trend of measured values of Young’s modulus is observed for smaller thickness samples.

In situ measurement of Young’s modulus of FeO scale formed on pure iron at 973–1273K by acoustic resonance method

2011 ◽  
Vol 53 (1) ◽  
pp. 458-463 ◽  
Author(s):  
Isao Saeki ◽  
Takuto Ohno ◽  
Ofuyu Sakai ◽  
Tetsuya Niya ◽  
Tadao Sato
Keyword(s):  
Young’S Modulus ◽  
Pure Iron ◽  
Young's Modulus ◽  
Resonance Method ◽  
Acoustic Resonance ◽  
In Situ Measurement

Scale effect and impact of discontinuities in the dynamic elastic constants of the Campanian chalk of Bougival (France)

2013 ◽  
Vol 184 (4-5) ◽  
pp. 347-355
Author(s):  
Róbert Porjesz ◽  
Françoise Bergerat
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Scale Effect ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Overburden Rock

Abstract Physical properties of in situ rock mass are usually estimated from results obtained through laboratory tests on intact rock samples because the access to in situ rock may be quite challenging. This approach however raises some questions concerning the number of samples needed for reliable result, the validity of the extrapolation of the parameters from centimetre scale to a large rock mass and finally the effect of discontinuities contained in the rock mass. An underground quarry in Bougival with easy access to metre-scale pillars and the possibility to collect large number of samples has been chosen to analyse the scale effect and the anisotropy of the Campanian chalk. Different experiments have been designed to determine the dynamic elastic properties (Young’s modulus and Poisson’s ratio) based on geophysical approaches: ultrasonic measurements on laboratory samples, and “hammer” seismic measurements in situ. The static Young’s modulus and Poisson’s ratio have been determined through uniaxial compression tests on centimetre core samples. Pillars with and without visible discontinuities, as well as with various overburden rock thicknesses, have been chosen in order to analyse the possible impact of different heterogeneities on the elastic properties. Core samples of intact chalk, with 40mm to 100mm diameters, have been studied in laboratory. The high dispersion observed on the different results suggests that if only a few tests are analysed, the conclusions may not be representative. A statistical approach is more appropriate to analyse the mechanical properties of the chalk. The dynamic Young’s Modulus and Poisson’s ratio calculated from laboratory samples (centimetres) and in situ rocks (about ten metres) do not reveal any clear impact of size on these elastic properties. The presence of discontinuities has a major impact on both the dynamic Young’s modulus and Poisson’s ratio. Decreasing values of these properties have been observed where discontinuities (fractures, flints) have been detected. Finally, the overburden rock thickness above the underground quarries (from 14m to 50m) seems to have no effect on the mechanical properties; the uncertainty of the measurements, partly due to the heterogeneity of the chalk mass, is likely to be more important than the effect of load on the pillars.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

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.

An analysis of the transport properties and mechanical stability of rapidly solidified Al-Sb alloy

2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Melt Spinning ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Microstructural Analysis ◽  
Alloy System ◽  
Antimony Content ◽  
The Stability ◽  
Rapidly Solidified

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 

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