Does Anyone Know The Real Fracture Toughness? SRM 2100: The World's First Ceramic Fracture Toughness Reference Material

2009 ◽  
pp. 76-76-17 ◽  
Author(s):  
GD Quinn ◽  
K Xu ◽  
RJ Gettings ◽  
JA Salem ◽  
JJ Swab
Keyword(s):  
Fracture Toughness ◽  
Reference Material ◽  
Ceramic Fracture ◽  
The Real

Fracture Toughness of Large Forgings for Power Producing Industry

2013 ◽  
Vol 577-578 ◽  
pp. 593-596 ◽  
Author(s):  
Václav Mentl
Keyword(s):  
Fracture Toughness ◽  
Chemical Composition ◽  
Steam Turbine ◽  
Mechanical Treatment ◽  
Material Degradation ◽  
The Real ◽  
Operational Safety ◽  
Local Properties ◽  
Thermo Mechanical Treatment ◽  
Shape And Size

The steam turbine rotors represent large components both in radial and axial directions. Their local properties generally differ from one forging to another, or if we compare head and bottom parts of the original ingot, or central and circumferential localities of one rotor body respectively, or if we compare the properties of separate discs e.g. in the case of welded rotors. These differences stem from both even slight changes in the chemical composition (of separate heats or even within one ingot) and thermo-mechanical treatment and in the differences in technology with respect to the real shape and size of the forgings in question. In the paper, the consequences of the differences in fracture toughness characteristics in various rotor localities are discussed with respect to the rotors operational safety taking into account the existence of cracks and material degradation.

scholarly journals Study on Thermally Induced Crack Propagation Behavior of Functionally Graded Materials Using a Modified Peridynamic Model

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Fei Wang ◽  
Yu’e Ma ◽  
Yanning Guo ◽  
Wei Huang
Keyword(s):  
Fracture Toughness ◽  
Crack Propagation ◽  
Functionally Graded Materials ◽  
Initial Temperature ◽  
Functionally Graded ◽  
Thermal Crack ◽  
Graded Materials ◽  
Ceramic Fracture ◽  
Thermally Induced ◽  
Peridynamic Model

Peridynamic (PD) theory is used to study the thermally induced cracking behavior of functionally graded materials (FGMs). A modified thermomechanical peridynamic model is developed. The thermal crack propagation of a ceramic slab in quenching is calculated to validate the modified PD model. The results predicted by the modified PD model agree with previously published numerical and experimental ones. Compared with the original PD model, the calculation accuracy of the modified PD model for thermal cracking is improved. The thermal cracking in FGMs is also simulated. The effects of material shape, initial temperature, and ceramic fracture toughness on thermal crack propagation behaviors are studied. It can be found that the thermal cracks in FGMs are still in periodical and hierarchical forms. The metal materials in FGMs can prevent crack initiation and arrest the long cracks. The crack number tends to be increased with the increasing initial temperature, while the strengthened ceramic fracture toughness can decrease it.

Fracture Toughness of Highly Irradiated Pressure Vessel Steels in the Upper Shelf Temperature

2006 ◽  
Author(s):  
Hiroshi Matsuzawa ◽  
Toru Osaki
Keyword(s):  
Fracture Toughness ◽  
Chemical Composition ◽  
Reference Material ◽  
Fast Neutron ◽  
Pressure Vessel ◽  
Charpy Impact ◽  
Pressure Vessels ◽  
Shelf Energy ◽  
Pressure Vessel Steels ◽  
Reactor Pressure

Nine Reactor Pressure Vessel (RPV) Steels and four RPV weld were irradiated up to 1.2 × 1024n/m2 fast neutron fluence (E>1MeV), and their fracture toughness and Charpy impact energy were measured. As chemical compositions, such as Cu, are known to affect the fracture toughness reduction due to neutron exposure, the above steels were fabricated by changing chemical composition widely to cover the chemical composition of the RPV materials of the operating Japanese nuclear power plants. 2.7 mm thick compact specimens were used to measure the upper shelf fracture toughness of highly irradiated materials, and their Charpy upper shelf energy was also measured. By correlating Charpy upper shelf energy to fracture toughness, the upper shelf fracture toughness evaluation formulae for highly irradiated reactor pressure vessel steels were developed. Both compact and V-notched Charpy impact specimens were irradiated in a test reactor. The fast neutron flux above 1MeV was about 5 × 1016n/(m2s). Charpy impact specimens made of Japanese PWR reference material containing 0.09w% Cu were irradiated simultaneously. The upper shelf energy of the reference material up to the medium fluence level showed little difference in the reduction of upper shelf energy to that which had been in the operating plant and which was irradiated to the same fluence. The developed correlation formulae have been adopted in the Japan Electric Association Code as new formulae to predict the fracture toughness in the upper shelf region of reactor pressure vessels. They will be applied to time limited ageing analysis of low upper shelf reactor pressure vessels in Japan, on a concrete technical basis in very high fluence regions.

Evaluation of Through Wall Fracture Toughness Distribution of IAEA Reference Material JRQ by Mini-C(T) Specimens and the Master Curve Method

2018 ◽  
Author(s):  
Masato Yamamoto ◽  
Tomohiro Kobayashi
Keyword(s):  
Fracture Toughness ◽  
Reference Material ◽  
Master Curve ◽  
Structural Integrity ◽  
Crack Edge ◽  
Temperature History ◽  
Integrity Assessment ◽  
Master Curve Method ◽  
Edge Location ◽  
Mc Method

The load and temperature history during pressurized thermal shock (PTS) event is highly depending on the crack edge location in wall thickness direction of a reactor pressure vessel (RPV) beltline region. Therefore, the consideration of plant specific through-wall fracture toughness distribution, which is not considered in the current codes and regulations [1,2], may improve the structural integrity assessment for PTS event. The Master Curve (MC) method [3,4] is one of the methods, which can directory evaluate the fracture toughness of ferritic materials with relatively low number of any size of specimens. CRIEPI has proposed the use of very small C(T) (Mini-C(T)) specimens for the MC method. The appropriateness of Mini-C(T) technology has been demonstrated through a series of researches and round robin activities [5, 6, 7, 8, 9]. The present study evaluated the through-wall fracture toughness distribution of irradiated IAEA reference material (JRQ) by means of combination of MC method and Mini-C(T) specimens. Four thickness locations between inner surface to 1/4-T was selected. Those four layers were separately subjected to the Mini-C(T) MC evaluation in two different laboratories. Both laboratories could separately obtain valid and consistent reference temperature, To, from all the tested layers. Inner most layer exhibits 80 °C lower To compared to the 1/4-T location even though the layer has the highest fluence of 5.38 × 1019 n/cm2, while that in 1/4-T location is 2.54 × 1019 n/cm2. The results demonstrate that initial toughness distribution is dominant in the general trend of fracture toughness distribution even after the material was highly irradiated.

Standard Reference Material 2100: Fracture Toughness of Ceramics

2009 ◽  
pp. 336-336-15
Author(s):  
GD Quinn ◽  
K Xu ◽  
R Gettings ◽  
JA Salem ◽  
JJ Swab
Keyword(s):  
Fracture Toughness ◽  
Reference Material ◽  
Standard Reference Material

scholarly journals Comparison of the indentation strength and single-edge-v-notched beam methods for dental ceramic fracture toughness testing

2017 ◽  
Vol 15 (2) ◽  
pp. 109 ◽  
Author(s):  
Natália Bertolo Domingues ◽  
Beatriz Regalado Galvão ◽  
Sebastião Ribeiro ◽  
Antonio Alves de Almeida Junior ◽  
Diogo Longhini ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Cooling Rate ◽  
Measurement Technique ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Measuring Method ◽  
Single Edge ◽  
Ceramic Fracture ◽  
Temperature Fracture ◽  
Toughness Testing

Aim: To study influence of the cooling rate after sintering a veneering porcelain (Vita VM9) on fracture toughness by indentation strength (IS) and single-edge-v-notched beam (SEVNB) methods. Methods: Vita VM9 bars were sintered according to the manufacturer’s recommendation and cooled under three conditions: Slow (inside the furnace from sintering temperature to room temperature); Normal (inside the furnace from sintering temperature to 500 ºC and outside the furnace from 500 ºC to room temperature); and Fast (outside the furnace from sintering temperature to room temperature). Fracture toughness was measured by IS (n=10) and SEVNB (n=10) methods. Data were analyzed by two-way ANOVA (α=0.05). Results: The fracture toughness obtained from SEVNB (slow - 1.02±0.10; normal - 1.09±0.13; and fast - 1,02±0.18 MPa.m1/2 cooling techniques) was significantly lower than IS (slow - 1.19±0.13; normal - 1.17±0.07; and fast - 1.16±0.06 MPa. m1/2 cooling techniques). There was no significant influence of the cooling technique (p=0.012). Conclusions: The measurement technique influenced the fracture toughness values . IS method overestimated the fracture toughness values. Irrespective of the measuring method, cooling rate did not influence the Vita VM9 veneering porcelain fracture toughness.

Measuring the Real Fracture Toughness of Ceramics: ASTM C 1421

2005 ◽  
pp. 531-553 ◽  
Author(s):  
Jonathan Salem ◽  
George Quinn ◽  
Michael Jenkins
Keyword(s):  
Fracture Toughness ◽  
The Real

Standard Reference Material 2100: Fracture Toughness of Ceramics

2005 ◽  
pp. 499-529 ◽  
Author(s):  
George D. Quinn ◽  
Kang Xu ◽  
Robert Gettings ◽  
Jonathan A. Salem ◽  
Jeffrey J. Swab
Keyword(s):  
Fracture Toughness ◽  
Reference Material ◽  
Standard Reference Material

Preparation and Mechanical Properties of ReAl11O18 Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 345-348
Author(s):  
Jun Dong Zhang ◽  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
Xin Min ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Bulk Density ◽  
Room Temperature ◽  
Pressureless Sintering ◽  
Optimal Temperature ◽  
Flexure Strength ◽  
The Real

In this paper, plate-like ReAl11O18 (Re = La, Pr, Nd) toughened ceramics were prepared by pressureless sintering at 1650 °C for 5 h in air. The bulk densities of the sintered samples were between 4.7 to 5.3g/cm3. The mechanical properties of the ReAl11O18 ceramics were studied systematically at room temperature. The flexure strength and fracture toughness of ReAl11O18 ceramics were 97.5 to 102.7 Mpa and 3.8 to 4.2Mpa.m1/2. The results show that: The optimal temperature to synthesis ReAl11O18 ceramics was 1650 °C; The flexural strength and fracture toughness of the ReAl11O18 ceramics increase with the increasing of its bulk density.

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