Effects of α-Decay on Mechanical Properties of Simulated Nuclear Waste Glass

1992 ◽  
Vol 294 ◽  
Author(s):  
Y. Inagaki ◽  
H. Furuya ◽  
Y. Ono ◽  
K. Idemitsu ◽  
T. Banba ◽  
...  

ABSTRACTA simulated nuclear waste glass was self-irradiated by doping with short-lived actinides of 238Pu and 244Cm. Changes in the hardness, the Young's modulus and the fracture toughness, as a function of irradiation dose, were measured by use of indentation techniques. The irradiated glass was annealed at temperatures from 573K to 723K for periods of up to 48hours, and the recovery of these changes were measured as a function of annealing temperature and time.It was observed that the hardness and the Young's modulus decreased, while the fracture toughness increased exponentially with the cumulative dose. The maximum values of the relative changes in the hardness, the Young's modulus and the fracture toughness were about −25%, −30% and +45%, respectively. The results of the annealing show that the hardness and the Young's modulus were almost recovered to the original values at temperatures above 673K within 10 hours, while the recovery of the fracture toughness was minimal in this region of temperature and time. The changes in the hardness and the Young's modulus can be well explained by the model, in which the changes is proportional to the volume fraction of damaged zones, F, and the recovery of F is first order. On the other hand, the changes in the fracture toughness cannot be explained by the model, which suggests that the mechanism of the change in the fracture toughness is different from that in the hardness and the Young's modulus.

2006 ◽  
Vol 317-318 ◽  
pp. 305-308 ◽  
Author(s):  
Rak Joo Sung ◽  
Takafumi Kusunose ◽  
Tadachika Nakayama ◽  
Yoon Ho Kim ◽  
Tohru Sekino ◽  
...  

A novel transparent polycrystalline silicon nitride was fabricated by hot-press sintering with MgO and AlN as additives. The mixed powder with 3 wt.% MgO and 9 wt.% AlN was sintered at 1900oC for 1 hour under 30 MPa pressure in a nitrogen gas atmosphere. Transparent polycrystalline silicon nitride was successfully fabricated. The mechanical properties such as density, hardness, young’s modulus, fracture strength and fracture toughness were evaluated. The effect of α/β phase on the mechanical properties of transparent polycrystalline silicon nitride was investigated. The properties were changed depending on the amount of α/β phase. The hardness and Young's modulus increased with increasing the volume fraction of α-phase fraction as a reflection of the higher hardness of α-phase Si3N4. The fracture toughness and fracture strength decreased with decreasing the volume fraction of β-phase Si3N4.


2011 ◽  
Vol 462-463 ◽  
pp. 100-105 ◽  
Author(s):  
Tomoyuki Fujii ◽  
Keiichiro Tohgo ◽  
Hiroyasu Araki ◽  
Katsunori Wakazono ◽  
Masaki Ishikura ◽  
...  

This paper deals with fabrication and strength evaluation of biocompatible composites consisting of partially stabilized zirconia (PSZ) and pure titanium (Ti). The biocompatible composites of PSZ-Ti were fabricated by a hot pressing method of powder metallurgy. A volume ratio of PSZ and Ti was changed. Four-point bending tests and Vickers hardness tests of the PSZ-Ti composite were performed to determine the Young's modulus, bending strength, Vickers hardness and fracture toughness. These properties were characterized as a function of Ti volume fraction. The Young's modulus and Vickers hardness were higher than the prediction of the rule of mixture. The bending strength and fracture toughness were decreased with increasing Ti content. To discuss these results from a viewpoint of reaction products, the components of raw powders and sintered composites were investigated by X-ray diffraction analysis. It is concluded that oxide of titanium and other reaction products were created after sintering and they affected the mechanical performances of the composites.


2017 ◽  
Vol 33 (1-2) ◽  
pp. 53 ◽  
Author(s):  
A. Kaouka ◽  
K. Benarous ◽  
A. Daas ◽  
S. A. Tsipas

The effects of Nb and Mo addition, with different contents, on the microstructure and some mechanical properties of Ti-6Al-4V alloy were investigated. Treatments were performed at various high temperatures about 1200 and 1300 °C for 3h using vacuum furnace as first treatment and using an argon atmosphere as second treatment. The samples were characterized by X-ray diffraction and the influence of processing temperature on microstructure was studied, the microstructural evolution was evaluated by optical microscopy and SEM. The results revealed that the Nb and Mo elements added to the titanium alloy stabilized the β phase and changed the lattice parameters of α phase. Microstructural observations, phase analysis shown that Ti-6Al-4V alloy contain single phase and increasing Nb and Mo contents the equiaxed grain is refined, and reduction in the prior β grain size. Moreover, Nb/Mo addition up to 10 wt.% increases the volume fraction of β phase in the microstructure. Some mechanical properties such as hardness, Young's modulus and fracture toughness were achieved and tensile test was performed at room temperature. Experimental results revealed good mechanical properties including a low Young's modulus and high deformability, the hardness values of the alloy is about 350-570 HV and the fracture toughness values K<sub>IC</sub> are ranging from 16.8 MPa m<sup>1/2</sup> to 28.5 MPa m<sup>1/2</sup> depending on Nb/Mo contents.


2005 ◽  
Vol 297-300 ◽  
pp. 1516-1521 ◽  
Author(s):  
Keiichiro Tohgo ◽  
Takayuki Kawaguchi

In order to estimate distribution of mechanical properties and fracture toughness in ceramic-metal functionally graded materials (FGMs), mechanical properties and fracture behavior have been investigated on non-graded ceramics-metal composites which correspond to each region of FGMs. The materials are fabricated by powder metallurgy using partially stabilized zirconia (PSZ) and stainless steel (SUS 304). Vickers hardness, Young’s modulus and bending fracture strength were examined on smooth specimens. The Vickers hardness of the composites continuously decreases with an increase in a volume fraction of SUS 304 metal phase, while the Young’s modulus and fracture strength exhibit low values in the composites with balanced composition of each phase. This suggests that the interfacial strength between the ceramic and metal phases is very low. Fracture toughness tests are conducted by three-point-bending on rectangular specimens with a sharp edgenotch. In contrast with the Young’s modulus and fracture strength, the fracture toughness obtained for the composites increases with an increase in a volume fraction of SUS 304 metal phase. The fracture toughness of the composites is slightly lower than that obtained previously by stable crack growth in a PSZ-SUS 304 FGM. The difference in fracture toughness between the composites and FGM seems to be attributed to the residual stress created during fabrication of the FGM.


2008 ◽  
Author(s):  
Sergey Stefanovsky ◽  
Alexander Barinov ◽  
Galina Varlakova ◽  
Irene Startseva ◽  
Michael I. Ojovan

2014 ◽  
Vol 7 ◽  
pp. 3-9 ◽  
Author(s):  
Étienne Vernaz ◽  
Jérôme Bruezière

1993 ◽  
Vol 333 ◽  
Author(s):  
A. Abdelouas ◽  
J. L. Crovisier ◽  
W. Lutze ◽  
R. Müller ◽  
W. Bernotat

ABSTRACTThe R7T7 and synthetic basaltic glasses were submitted to corrosion in a saline MgCl2dominated solution at 190°C. For both glasses, the early alteration product is a hydrotalcite-like compound in which HPO42-, SO4-2and Cl-substitutes to CO32. The measured d003spacing is 7.68 Å for the hydrotalcite formed from R7T7 glass and 7.62 Å for the hydrotalcite formed from basaltic glass which reflect the high aluminium content. Chemical microanalyses show that the hydrotalcite is subsequently covered by a silica-rich gel which evolves into saponite after few months.


2021 ◽  
Vol 21 (2) ◽  
pp. 7-11
Author(s):  
Ahmed Mansoor Abbood ◽  
Haider K. Mehbes ◽  
Abdulkareem. F. Hasan

In this study, glass-filled epoxy functionally graded material (FGM) was prepared by adopting the hand lay-up method. The vertical gravity casting was used to produce a continuous variation in elastic properties. A 30 % volume fraction of glass ingredients that have mean diameter 90 μm was spread in epoxy resin (ρ = 1050 kg/m3). The mechanical properties of FGM were evaluated according to ASTM D638. Experimental results showed that a gradually relationship between Young’s modulus and volume fraction of glass particles, where the value of Young’s modulus at high concentration of glass particles was greater than that at low concentration, while the value of Poisson’s ratio at high concentration of glass particles was lower than that at low concentration. The manufacture of this FG beam is particularly important and useful in order to benefit from it in the field of various fracture tests under dynamic or cyclic loads.


2013 ◽  
Vol 761 ◽  
pp. 83-86
Author(s):  
Hideaki Sano ◽  
Junichi Morisaki ◽  
Guo Bin Zheng ◽  
Yasuo Uchiyama

Effects of carbon nanotubes (CNT) addition on mechanical properties, electric conductivity and oxidation resistance of CNT/Al2O3-TiC composite were investigated. It was found that flexural strength, Young’s modulus and fracture toughness of the composites were improved by addition of more than 2 vol%-CNT. In the composites with more than 3 vol%-CNT, the oxidation resistance of the composite was degraded. In comparison with Al2O3-26vol%TiC sample as TiC particle-percolated sample, the Al2O3-12vol%TiC-3vol%CNT sample, which is not TiC particle-percolated sample, shows almost the same mechanical properties and electric conductivity, and also shows thinner oxidized region after oxidation at 1200°C due to less TiC in the composite.


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