Error Analysis of Ceramic Materials Fracture Toughness Measured by the Single Edge Notched Beam Method

2014 ◽  
Vol 1004-1005 ◽  
pp. 434-437 ◽  
Author(s):  
Jia Liang Wang ◽  
Xian Feng Shen ◽  
Meng Liang Bai ◽  
Gang Zhou ◽  
Mian Jiang

In this study, the fracture toughness of ceramic materials such as Al2O3, SiC, Si3N4, ZrO2 were measured by the SENB method and IF method respectively. The results shown that the value of fracture toughness obtained from the SENB method is significantly higher than the IF method. When the notch width is fixed, with the flexural strength of ceramic materials increasing, the error of fracture toughness from the SENB method compared to the IF method is increased. For example, the flexural strength of ZrO2 is about 847MPa and the error of fracture toughness from the SENB method compared to the IF method is 50.14%, the flexural strength of Al2O3 is about 338MPa and the error of fracture toughness from the SENB method compared to the IF method is only 4.52%.

2009 ◽  
Vol 409 ◽  
pp. 17-27 ◽  
Author(s):  
Roger Morrell

Using a variety of advanced ceramic materials, a comparison has been conducted of fracture toughness test methods using the single edge vee-notch beam method and the surface crack in flexure method, the latter restricted to optical fractography. Good agreement has been found between the two methods on materials which were amenable to the SCF method. It has further been shown that the SEVNB method can produce reliable results on materials to which the SCF method is not readily applicable.


1986 ◽  
Vol 78 ◽  
Author(s):  
T. W. Coyle ◽  
R. P. Ingel ◽  
P. A. Willging

ABSTRACTThe flexural strength and the single edge notch beam fracture toughness of undoped ZrO2 crystals, grown by the skull melting technique, were examined from room temperature to 1400°C. On heating the toughness increased with test temperature to a maximum of 4.0 MPajm at 1225°C then gradually decreased to 2.6 MPa/m. Upon cooling after a 20 minute hold at 1250°C an increase in toughness to 5 MPa/m was observed at 1200°C; upon cooling to lower temperatures Kic gradually diminished. The loaddeflection curves for the flexural strength tests showed marked nonlinearity before failure for samples tested on cooling. The temperature dependence of the apparent yield stress suggests that initial yielding occurs by slip above 1200°C but that from 1200°C to 1050°C the observed yielding is due to stress induced tetragonal to monoclinic transformation.


2012 ◽  
Vol 500 ◽  
pp. 623-628 ◽  
Author(s):  
Yu Huan Fei ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou

Al2O3-TiN-TiC ceramic materials with different MgO content were fabricated by hot-pressing technique. The MgO volume percent was varied from 0vol% to 5vol%. The mechanical properties such as flexural strength, Vickers hardness and fracture toughness were tested. The phase composition of the sintered body was analyzed by XRD while the microstures of the sintering body were observed by OM (Optical Microscope) and SEM. The effects of MgO content on the mechanical properties and microstructures of Al2O3-TiN-TiC were investigated. The results shows that the addition of MgO can change the phase composition of the sintered ceramic materials which displayed with diverse solid solutions and intermetallic compounds. Meanwhile the new sintering products changed the the microstructure morphology which made the crack path complex and affected the mechanical properties.


2007 ◽  
Vol 280-283 ◽  
pp. 1745-1750
Author(s):  
Chun Hong Chen ◽  
Hideo Awaji

A novel estimation for the critical size of the frontal process zone of ceramics is proposed using a single-edge V-notched beam (SEVNB) technique. A three-point flexure test is carried out on aluminum titanate ceramics containing a sharp V-shaped notch with different depth. An exact solution of the critical local stress is analyzed at a critical distance from the notch tip. The critical frontal process zone size is determined as the distance between the notch tip and the point where the critical local stress equals the flexural strength of specimens without notches, based on the local fracture criterion and the Griffith-Irwin criterion. The critical size of the frontal process zone, the fracture toughness and the flexural strength were also estimated for several materials, such as, alumina, porous alumina, and alumina-based nanocomposites. The relationship between these mechanical properties indicated that there was an almost linear relationship between the fracture toughness and the resultant of strength and square root of the critical frontal process zone size, and that both of them must be increased to improve the fracture toughness of ceramics.


2012 ◽  
Vol 457-458 ◽  
pp. 3-6
Author(s):  
Yu Huan Fei ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou

Al2O3-TiN-TiC ceramic materials with different MgO content were fabricated by hot-pressing technique. The MgO volume percent was varied from 0vol% to 5vol%. Three point bending test was applied to get the flexural strength and the Vickers indentation was applied to get the Vickers hardness and the fracture toughness. The phase composition of the ceramics was analyzed by XRD. The effects of the content of MgO on the mechanical properties and the phase composition of Al2O3-TiN-TiC were investigated. The results shows that the addition of MgO can change the phase composition of the sintered ceramic materials which displayed with diverse solid solutions and intermetallic compounds. The convertion of the mechanical properties can also be explained by the XRD results.


2013 ◽  
Vol 745-746 ◽  
pp. 560-564
Author(s):  
Wen Bo Han ◽  
Peng Wang ◽  
Yang Hou

ZrB2-based ceramic composites were prepared through hot-pressing at a temperature of 1880°C. An intragranular microstructure was achieved because of the existence of nanoSiC. In this paper, the mechanical properties of ceramic materials of ZrB2-SiC-G were studied, and the influence of intragranular microstructure on the mechanical properties was analyzed. The values of flexural strength and fracture toughness of ZrB2-20vol%SiCnp-15vol%G reached 551.9MPa and 5.25MPa·m1/2, respectively. Compared to ZrB2-20vol%SiC-15vol%G with micro-SiC, the fracture toughness was improved.


1990 ◽  
Vol 56 (525) ◽  
pp. 1148-1153 ◽  
Author(s):  
Hideo AWAJI ◽  
Tadao WATANABE ◽  
Tatsuya YAMADA ◽  
Yoshihisa SAKAIDA ◽  
Hiromiti TAMIYA ◽  
...  

2013 ◽  
Vol 320 ◽  
pp. 599-606 ◽  
Author(s):  
Li Juan Wang ◽  
Jin Sheng Liang ◽  
Xing Fu Di ◽  
Xue Mei Pei

The effects of sepiolite mineral nanofiber on strength and toughness of ceramics were investigated by bone china with addition of sepiolite mineral nanofiber. The flexural strength and fracture toughness were tested by three point bending method and single edge notched beam (SENB) method, and the microstructure of the ceramics was studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and optical microscopy. The results indicated that the structure pattern of sepiolite mineral nanofiber became much shorter and thicker after calcinations. Proper addition of sepiolite mineral nanofiber would increase the strength and toughness of bone china. The sepiolite mineral nanofiber can yield the bone china with fracture toughness and flexural strength values as high as 5.65 MPa·m1/2and 112.66 MPa to 5.87 MPa·m1/2and 118.90 MPa, mainly due to crack bridging, crack deflection and pullout by sepiolite mineral nanofiber.


2013 ◽  
Vol 770 ◽  
pp. 308-311 ◽  
Author(s):  
Ming Dong Yi ◽  
Chong Hai Xu ◽  
Zhao Qiang Chen ◽  
Guang Yong Wu

A new nanomicro composite self-lubricating ceramic tool material was prepared with vacuum hot pressing technique. The effect of nanoAl2O3 powders on the microstructure and mechanical properties of nanomicro composite self-lubricating ceramic tool material was investigated. With the increase of nanoAl2O3 content, the hardness and fracture toughness first up then down. When the nanoAl2O3 content is 4 vol.%, the flexural strength, hardness and fracture toughness reaches 562 MPa, 8.46 MPa·m1/2 and 18.95 GPa, respectively. The microstructure and mechanical property of nanomicro composite self-lubricating ceramic tool material can be improved by the grain refinement strengthening of nanoAl2O3.


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