Filters
Results 1 - 10 of 2690
Results 1 - 10 of 2690.
Search took: 0.024 seconds
Sort by: date | relevance |
Hayashi, Kazunori; Tachi, Yoshiaki; Kano, Shigeki; Hirakawa, Yasushi; Komine, Ryuji; Yoshida, Eiichi
Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)1998
Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)1998
AbstractAbstract
[en] Engineering ceramics have excellent properties such as high strength, high hardness and high heat resistance compared with metallic materials. To apply the ceramic in fast reactor environment, it is necessary to evaluate the sodium compatibility and the influence of sodium on the mechanical properties of ceramics. In this study, the influence of high temperature sodium on the mechanical properties of sintered ceramics of conventional and high purity Al2O3, SiC, SiAlON, AlN and unidirectional solidified ceramics of Al2O3/YAG eutectic composite were investigated by means of flexure tests. Test specimens were exposed in liquid sodium at 823K and 923K for 3.6Ms. There were no changes in the flexural strength of the conventional and high purity Al2O3, AlN and Al2O3/YAG eutectic composite after the sodium exposure at 823K. On the contrary, the decrease in the flexural strength was observed in SiC and SiAlON. After the sodium exposure at 923K, there were also no changes in the flexural strength of AlN and Al2O3/YAG eutectic composite. In the conventional and high purity Al2O3 and SiC, the flexural strength decreased and signs of grain boundary corrosion were detected by surface observation. The flexural strength of SiAlON after the sodium exposure at 923K increased instead of severe corrosion. In the specimens those showed no changes in the flexural strength, further exposure in sodium is needed to verify whether the mechanical properties degrade or not. For SiAlON, it is necessary to clarify the reason for the increased strength after the sodium exposure at 923K. (author)
Primary Subject
Source
Feb 1998; 75 p
Record Type
Report
Report Number
Country of publication
ALKALI METALS, BREEDER REACTORS, CHEMICAL REACTIONS, COHERENT SCATTERING, CORROSION, DIFFRACTION, ELECTRON MICROSCOPY, ELEMENTS, EPITHERMAL REACTORS, FAST REACTORS, FBR TYPE REACTORS, FLUIDS, LIQUID METAL COOLED REACTORS, LIQUIDS, MATERIALS, MECHANICAL PROPERTIES, METALS, MICROSCOPY, REACTORS, SCATTERING, SPECTROSCOPY, TEMPERATURE RANGE
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Melo, F.C.L.; Cairo, C.A.C.; Devezas, T.C.; Nono, M.C.A.
Universidade Estadual de Campinas, SP (Brazil)1988
Universidade Estadual de Campinas, SP (Brazil)1988
AbstractAbstract
[en] In order to study the mechanical properties of tetragonal polycrystal zirconia stabilized with ceria various powder compositions with different CeO2 content were made. Modulus of rupture for those compounds was measured. Tetragonal retained phase was determined for samples of CeO2-ZrO2 ceramics with and without superficial mechanical treatment. The experimental results allowed us to evaluate the effects of CeO2 content and sintering temperature in the mechanical properties and tetragonal transformed phase (t→ m) in ceramics of CeO2-ZrO2 systems. (author)
[pt]
Com objetivo de se avaliar as proppriedades mecanicas de conjugados ceramicos de zirconia tetragonal policristalina estabilizada com ceria, formularam-se composicoes de pos variando o teor de Ce2O2, seguidas de mistura mecanica, compactacao isostatica e sinterizacao em diversas temperaturas. Foram medidas a tensao de ruptura e a determinacao da fracao de fase tetragonal retida em amostras com e sem tratamento mecanico superficial. Os resultados obtidos, permitiram uma avaliacao da influencia do teor de Ce2O2 e da temperatura de sinterizacao nas propriedades mecanicas e retencao de fase tetragonal em conjugados ceramicos CeO2-ZrO2. (autor)Original Title
Conjugados ceramicos CeO2-ZrO2
Primary Subject
Source
1988; 3 p; 8. Brazilian Congress on Engineering and Materials Science; Campinas, SP (Brazil); 12-15 Dec 1988; Available from the Library of Comissao Nacional de Energia Nuclear, RJ, Brazil
Record Type
Miscellaneous
Literature Type
Conference
Country of publication
LanguageLanguage
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] The effect of free chromium oxide on the change of properties of lanthanum chromite ceramics La0.95Ca0.05CrO3 at high temperature is studied. The stability of properties is estimated by changes in porosity mass losses and electric conductivity after thermal treatment at 1600-1700 dec C. It is established that to increase the stability of ceramics properties it is advisable to use molten materials with the minimum content of free chromium oxide in the initial charge
Original Title
Vliyanie svobodnogo oksida khroma na nekotorye svojstva keramiki iz khromita lantana
Primary Subject
Record Type
Journal Article
Journal
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] The room temperature slow crack growth resistance in air (approx. 50% relative humidity) and in water for large cracks in MgO-partially stabilized zirconia (PSZ) improves with increase in critical fracture toughness, Ksub(Ic). Ageing the as-fired PSZ at 1400 C for 8 h results in decreasing Ksub(Ic) from 8.5 MPa msup(1/2) to 6 MPa msup(1/2). The ageing treatment also promotes the growth of eutectoid decomposition products on grain boundaries that is accompanied by a decrease in the dependence of the change in Region 1 crack velocity with a change in the applied stress intensity. Calculated times to failures are markedly decreased in the aged as compared to the as-fired PSZ ceramic. (author)
Primary Subject
Source
CONTRACT DE-ACO5-840R21400
Record Type
Journal Article
Journal
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] A considerable decrease of elasticity modulus in Tb2Ti2O7 in the low-temperature range is found. It is shown that responsible for the effect are electron-deformation interaction and structure specificity of Tb3+ ion low energy levels in the Tb2Ti2O7 crystal lattice field. The estimation of critical temperature value of the cooperative Yahn-Teller effect in Tb2Ti2O7:Tc ≅ 0.1 K is given
Original Title
Nizkotemperaturnaya anomaliya uprugogo modulya v Tb2Ti2O7
Primary Subject
Source
For English translation see the journal JETP Letters (USA).
Record Type
Journal Article
Journal
Pis'ma v Zhurnal Ehksperimental'noj i Teoreticheskoj Fiziki; ISSN 0370-274X;
; CODEN PZETA; v. 43(12); p. 584-586

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] An etch-pitting technique has been used to compare the dislocation distribution around unrecovered, i.e. with a load still applied to the indenter, and recovered impressions in single crystal MgO. Thus it is shown that, immediately upon removing normal loads greater than 100 g (0.98 N), additional slip lines are developed on the surface surrounding the actual indentation. Reversed plastic flow, in previously undeformed material adjacent to the region which has become work-hardened during the formation of the impression, is considered to be responsible for this phenomenon. It is suggested that this effect is caused by elastic recovery in the work-hardened region as the load is removed. Whilst this appears to have a negligible effect on the accuracy of hardness measurements, it could be an important contribution to cumulative processes of deformation and fracture as in comminution and wear. (author) 23 refs., 3 figs
Primary Subject
Source
Indentation fracture and mechanical properties of ceramic fuels and of waste ceramics and glasses; Karlsruhe (Germany, F.R.); 11-12 Nov 1985; EUR--10597
Record Type
Journal Article
Literature Type
Conference
Journal
European Applied Research Reports-Nuclear Science and Technology Section; ISSN 0379-4229;
; CODEN EARRD; v. 7(7); p. 1147-1157

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] Ceramic test specimens with controlled surface flaws introduced by Knoop indentation are being increasingly used in fracture mechanical investigations. Such artificially induced cracks must have the same characteristics as cracks of natural origin. A problem of transferability is caused by the existence of a damaged surface zone which acts as a wedge. In the theoretical part the effect of wedging on crack opening behaviour is treated. In the experimental part first the removal of residual stress effects due to wedging is described and finally the application of Knoop cracked specimens to lifetime measurements under static load is demonstrated. The experimental part deals with aluminum oxide. (author) 7 refs., 6 figs
Primary Subject
Source
Indentation fracture and mechanical properties of ceramic fuels and of waste ceramics and glasses; Karlsruhe (Germany, F.R.); 11-12 Nov 1985; EUR--10597
Record Type
Journal Article
Literature Type
Conference
Journal
European Applied Research Reports-Nuclear Science and Technology Section; ISSN 0379-4229;
; CODEN EARRD; v. 7(7); p. 1183-1196

Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] A new application of a.c. impedance technology for monitoring crack propagation was discovered in this study, and this methodology was patented. By excluding ranges of frequency, a single frequency was chosen to monitor crack propagation of sensitized 304 stainless steel in thiosulfate solution. The behavior of the phase angle from the impedance data gives interesting information regarding crack growth. Generally, the phase angle tends to rise if the crack propagates continuously. Computer simulation showed that the phase shift was caused by the variation of the capacitance in the equivalent circuit. ((orig.))
Primary Subject
Record Type
Journal Article
Journal
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] Plates of SiC, TiB2 and Al2O3 were impacted edge-on with steel projectiles at striking velocities between 20 m/s and 1000 m/s. Fracture propagation in the specimen was visualised by means of a Cranz-Schardin camera within the first twenty microseconds. The phenomenology of damage is discussed and compared for the different types of ceramics. The velocities of single cracks and crack fronts were measured. The experiments were supplemented by ceramographical investigations of recovered fragments. Void nucleation and coalescence could be identified as the failure mechanism in impacted TiB2. (orig.)
Primary Subject
Source
1. international conference on mechanical and physical behaviour of materials under dynamic loading combining the 4. DYMAT conference on mechanical and physical behaviour of materials under dynamic loading and the 5. Oxford conference on mechanical properties of materials at high rates of strain (Euro Dymat); Oxford (United Kingdom); 26-30 Sep 1994
Record Type
Journal Article
Literature Type
Conference
Journal
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
[en] Under certain high strain rate conditions, plastic deformation can be assumed to be adiabatic, and a significant temperature increase can occur at large strains. In this study, tantalum and tantalum-tungsten alloys were subjected to high shear strains at high strain rate using a specially-designed stepped specimen in a Hopkinson bar. Upon completion of the deformation, the region is cooled to below one-half of the temperature achieved due to the adiabatic heating in less than one millisecond. Microstructural analysis by transmission electron microscopy revealed that the highly deformed shear-band region consisted of a gradual decrease in dislocation cell size with increasing strain. An analysis based on dynamic recovery (enabled by the adiabatic temperatures rise associated with plastic deformation), is used to predict the recovered microstructure. (orig.)
Primary Subject
Source
1. international conference on mechanical and physical behaviour of materials under dynamic loading combining the 4. DYMAT conference on mechanical and physical behaviour of materials under dynamic loading and the 5. Oxford conference on mechanical properties of materials at high rates of strain (Euro Dymat); Oxford (United Kingdom); 26-30 Sep 1994
Record Type
Journal Article
Literature Type
Conference
Journal
Country of publication
BINARY ALLOY SYSTEMS, DEFORMATION, DISLOCATIONS, ELECTRON MICROSCOPY, MATHEMATICAL MODELS, MECHANICAL PROPERTIES, MICROSTRUCTURE, SHEAR PROPERTIES, STRAINS, TANTALUM, TANTALUM ALLOYS, TEMPERATURE DEPENDENCE, TEMPERATURE RANGE 0400-1000 K, TEMPERATURE RANGE 1000-4000 K, TRANSMISSION ELECTRON MICROSCOPY, TUNGSTEN ALLOYS
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
1 | 2 | 3 | Next |