IDENTIFICATION OF RESIDUAL STRESSESIN PRODUCTS FROM CARBON- CARBONACEOUSMATERIALS

2015 ◽  
Vol 2 (4) ◽  
pp. 0-0
Author(s):  
Анна Казначеева ◽  
Anna Kaznacheeva ◽  
Юлия Полинко ◽  
Yuliya Polinko
Keyword(s):  
Experimental Data ◽  
Phase Composition ◽  
Residual Stresses ◽  
Experimental Studies ◽  
Quality Criterion ◽  
Production Environment ◽  
Ray Method ◽  
X Ray ◽  
Artificial Graphite ◽  
Degree Of Graphitization

The method of assessing the level of residual stresses in graphitic carbon shell of revo-lution, by interpreting the experimental data obtained by the x-ray method is proposed. The results of experimental studies of mental-phase composition, the parameters of the crystal lattice, the degree of graphitization and texturing of pyrolytic reinforced carbon-carbonaceous composite are given. Estimation of the level of residual technological tensions resulting in defects of products has been performed at the micro and macro stages. Quality criterion is written as a deviation square sum, calculated and measured broa-dening of diffractogram lines. High informativity of the radiographic method for estimating artificial graphite prod-uct quality and the possibility of using this method in the production environment.

EVALUATION OF THE STRESSED DEFORMED STATE OF MAIN GAS PIPELINES RUNNING IN PERMANENTLY FROZEN GROUNDS

2020 ◽  
pp. 58-63
Author(s):  
M. M. Sidorov ◽  
N. I. Golikov ◽  
R. P. Tihonov
Keyword(s):  
Experimental Data ◽  
Calculated Data ◽  
Gas Pipeline ◽  
Loss Of Stability ◽  
Portable Equipment ◽  
Ray Method ◽  
X Ray ◽  
Deformed State ◽  
Pipeline Monitoring

The work evaluates the stress deformed state of the section of the interfield gas collecting main, running in permanently frozen grounds. The object of research is a section of a pipeline with an arched discharge formed as a result of loss of stability as a result of thermal erosion of permanently frozen grounds to disturbance of the vegetation cover. The determination of stresses was carried out by the X-ray method using portable equipment. The experimental data were analyzed with the calculated. The calculated data were obtained by measuring the spatial position of the gas pipeline section. The obtained values of the acting stresses and the estimates of the critical indicators of the gas pipeline monitoring section made it possible to reasonably estimate the stress state. The methodology for determining the acting stresses of pipelines using portable X-ray equipment can be successfully applied to estimate the stressed-deformed state of pipeline systems running in the zone of permafrost.

Measuring Residual Stress with the Indentation Method in Struc­tural Ceramics

2005 ◽  
Vol 297-300 ◽  
pp. 515-520
Author(s):  
Tarou Tokuda ◽  
Rong Gang Wang ◽  
Mitsuo Kido ◽  
Gonojo Katayama
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Phase Transformation ◽  
Residual Stresses ◽  
Treatment Method ◽  
Indentation Load ◽  
X Rays ◽  
Ray Method ◽  
Indentation Method ◽  
X Ray

This study deals with the indentation method of measuring residual stress in structural ceramics. First we investigate the appropriate pretreatment for measuring fracture toughness (basis value, KC) while avoiding any influence from residual stress, which is important when estimating residual stress using the indentation method. Based on the fracture toughness value, the residual stresses in Al2O3, Si3N4 and ZrO2 ceramics are estimated using the indentation method. Phase transformation is a problem when estimating residual stress using the indentation method with ZrO2 ceramics. Residual stresses in Al2O3 and Si3N4 can be largely eliminated by annealing the specimen after hand grinding. Consequently, it is thought that this treatment method is effective for determining the basis value KC. The estimated residual stress values in Al2O3 and Si3N4 obtained by the indentation method at 98 N corresponded closely to the values obtained wih X-rays. The residual stress value obtained by the indentation method for ZrO2 was close to the value obtained through the X-ray method, when the indentation load was 294 N. When estimating the residual stress in ZrO2 using the indentation method, the influence of the phase transformation caused by the indentation is added onto the original residual stress, when the indentation is small. The influence becomes smaller when the indentation load is large. If the applied indentation load is between 294 N and 490 N, the indentation method is effective for estimating the residual stresses in Al2O3, Si3N4 and ZrO2 ceramics.

THEORETICAL AND EXPERIMENTAL STUDIES ON SILOXENE

1993 ◽  
Vol 07 (21) ◽  
pp. 1343-1364 ◽  
Author(s):  
P. DEÁK ◽  
M. STUTZMANN ◽  
M. S. BRANDT ◽  
M. ROSENBAUER ◽  
S. FINKBEINER ◽  
...  
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Magnetic Resonance ◽  
Quantum Chemical ◽  
Experimental Studies ◽  
X Ray Diffraction ◽  
Absorption Coefficients ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Equilibrium Structures

Structural and optical properties of siloxene ( Si 6 O 3 H 6) and its derivatives obtained by chemical substitution or annealing are reviewed. The preparation of siloxene is briefly described and results of x-ray diffraction and infrared absorption are shown. The equilibrium structures of stoichiometric siloxene and the electronic properties of the corresponding 2, 1, and 0-dimensional Si-clusters are obtained from quantum chemical calculations and compared to other calculations. Experimental results concerning luminescence, luminescence excitation, absorption coefficients, magnetic resonance, and stability are presented. The origin of the optical properties of siloxene is discussed based on the accumulated experimental data and on the results of theoretical modeling.

scholarly journals Structure Determination of Ho2PdSi3

2014 ◽  
Vol 70 (a1) ◽  
pp. C224-C224
Author(s):  
Melanie Nentwich ◽  
Matthias Zschornak ◽  
Carsten Richter ◽  
Dmitri Novikov ◽  
Dirk Meyer
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Local Environment ◽  
Ray Method ◽  
X Ray ◽  
Metal Silicides ◽  
Wide Range ◽  
Site Selective ◽  
Palladium Silicide

Holmium-Palladium-Silicide Ho2PdSi3 is a member of rare earth-transition metal silicides exhibiting a wide range of interesting magnetic and electrical properties like multiple transition temperatues. The crystal structure results from HoSi2 by substitution of Si by Pd which is ordering commensurably with a 2 × 2 × 8 superstructure confirmed by a previous XRD and a Diffraction Anomalous Fine Structure (DAFS) measurement of the super structure reflection 1/2 1/2 3/8. DAFS is a X-ray method combining the advantages of absorption and diffraction and hence offers the possibility of element and site selective studies. Thus, it was feasible to probe the local environment of Ho and Pd separately. In the following, we will present a comparison of several structure proposals of Ho2PdSi3 with experimental data from beamline E2 and BW1 of the former synchrotron DORIS III at DESY/HASYLAB.

scholarly journals Theoretical and experimental studies of material radiative properties and their applications to laser and heavy ion inertial fusion

2011 ◽  
Vol 29 (1) ◽  
pp. 69-80 ◽  
Author(s):  
N. Yu. Orlov ◽  
O.B. Denisov ◽  
O.N. Rosmej ◽  
D. Schäfer ◽  
Th. Nisius ◽  
...  
Keyword(s):  
Experimental Data ◽  
Experimental Studies ◽  
Radiation Efficiency ◽  
Radiative Properties ◽  
Wall Material ◽  
Inertial Fusion ◽  
X Rays ◽  
X Ray ◽  
Wide Range ◽  
X Ray Absorption

AbstractTheoretical and experimental studies of radiative properties of substances heated by pulsed current devises or lasers and used as X-ray sources have been carried out depending on plasma conditions, and specific spectra of X-ray absorption and radiation for different materials have been calculated. Important features of the theoretical model, known as the ion model of plasma, are discussed. This model can be applied for calculations of the radiative properties of complex materials over a wide range of plasma parameters. For purposes of indirect-driven inertial fusion based on the hohlraum concept, an optimization method is used for the selection of an effective complex hohlraum wall material, which provides high radiation efficiency at laser interaction with the wall. The radiation efficiency of the resulting material is compared with the efficiency of other composite materials that have previously been evaluated theoretically. A similar theoretical study is performed for the optically thin X-pinch plasma produced by exploding wires. Theoretical estimations of radiative efficiency are compared with experimental data that have been obtained from measurements of X-pinch radiation energy yield using two exploding wire materials, NiCr and Alloy 188. It is shown that the theoretical results agree well with the experimental data. A symmetric multilayer X-pinch, where W and Mo wires are used, is as well considered. The theoretical explanation of experimental phenomena is discussed based on the W and Mo radiative spectra. The ion model was as well applied for interpretation of experimental results on opacities of CHO-plasma obtained via indirect heating of low density polymer layers by means of soft X-rays. The new diagnostics method based on the deformation of the of the Carbon absorption K-edge when foam layer is heated to plasma is discussed. The spectral coefficients for X-ray absorption in CHO-plasma are calculated in the photon energy region around the Carbon K-edge for different plasma temperatures and mean foam density. In this case, the Carbon K-edge position on the energy scale can be used for plasma temperature diagnostic.

scholarly journals Theoretical and experimental studies of the radiative properties of hot dense matter for optimizing soft X-ray sources

2007 ◽  
Vol 25 (3) ◽  
pp. 415-423 ◽  
Author(s):  
N.Yu. Orlov ◽  
S.Yu. Gus'kov ◽  
S.A. Pikuz ◽  
V.B. Rozanov ◽  
T.A. Shelkovenko ◽  
...  
Keyword(s):  
Experimental Data ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Dense Matter ◽  
Radiation Energy ◽  
Radiative Properties ◽  
Theoretical Research ◽  
Energy Yield ◽  
X Ray ◽  
Dense Plasmas

Theoretical and experimental studies of radiative properties of hot dense plasmas that are used as soft X-ray sources have been carried out depending on the plasma composition. Important features of the theoretical model, which can be used for complex materials, are discussed. An optimizing procedure that can determine an effective complex material to produce optically thick plasma by laser interaction with a thick solid target is applied. The efficiency of the resulting material is compared with the efficiency of other composite materials that have previously been evaluated theoretically. It is shown that the optimizing procedure does, in practice, find higher radiation efficiency materials than have been found by previous authors. Similar theoretical research is performed for the optically thin plasma produced from exploding wires. Theoretical estimations of radiative efficiency are compared with experimental data that are obtained from measurements of X-pinch radiation energy yield using two exploding wire materials, NiCr and Alloy 188. It is shown that theoretical calculations agree well with the experimental data.

scholarly journals Mesoscopic residual stresses of plastic origin in zirconium: interpretation of X-ray diffraction results

2004 ◽  
Vol 37 (6) ◽  
pp. 934-940 ◽  
Author(s):  
D. Gloaguen ◽  
M. François ◽  
R. Guillen
Keyword(s):  
Experimental Data ◽  
Plastic Deformation ◽  
Residual Stresses ◽  
Rolling Direction ◽  
Deformation Mode ◽  
Prismatic Slip ◽  
X Ray Diffraction ◽  
Active Deformation ◽  
X Ray ◽  
Self Consistent

Complementary methods have been used to analyse residual stresses in a heat-treated Zr702 sheet which had undergone uniaxial plastic deformation: X-ray diffraction and self-consistent models. The elastoplastic self-consistent model has been used to simulate the experiments and exhibits agreement with experimental data. X-ray diffraction analysis in the rolling direction shows opposite stress values for {10\bar{1}4} and {20\bar{2}2} planes, respectively. The measured strains were generated by an anisotropic plastic deformation. The comparison between ∊ϕψversussin2ψ and simulations confirms that prismatic slip is the main active deformation mode. Plastic incompatibility stress in X-ray measurements should be taken into account in order to make a correct interpretation of the experimental data.

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