Subcritical Crack Growth Velocities (v-K Curves) of Dental Bioceramics

2012 ◽  
Vol 727-728 ◽  
pp. 1211-1216 ◽  
Author(s):  
Humberto Naoyuki Yoshimura ◽  
Carla Cristina Gonzaga ◽  
Paulo Francisco Cesar ◽  
Walter Gomes Miranda
Keyword(s):  
Crack Growth ◽  
Growth Velocity ◽  
Ceramic Composite ◽  
Subcritical Crack Growth ◽  
Artificial Saliva ◽  
Glass Ceramics ◽  
Velocity Versus ◽  
Factor V ◽  
Alumina Composite ◽  
Crack Growth Velocity

In this study the subcritical crack growth (SCG) behaviors of five dental bioceramics were evaluated in order to plot the crack growth velocity versus stress intensity factor (v-K) curves. Disc-shaped samples of two sintered porcelains, two glass-ceramics, and a glass-infiltrated ceramic composite were prepared and tested in artificial saliva using a biaxial flexure jig. The SCG parameters were evaluated by the dynamic fatigue test using five constant stress-rates and in an inert condition. Among the tested materials, the lithium disilicate glass-ceramic showed the highest susceptibility to strength degradation by SCG, whereas the glass infiltrated alumina composite showed the lowest susceptibility. The v-K curves showed that the SCG susceptibility significantly affects the crack growth velocity of the different bioceramics.

A four-point bending technique for studying subcritical crack growth in thin films and at interfaces

1997 ◽  
Vol 12 (3) ◽  
pp. 840-845 ◽  
Author(s):  
Qing Ma
Keyword(s):  
Crack Growth ◽  
Growth Velocity ◽  
Crack Velocity ◽  
Subcritical Crack Growth ◽  
Beam Theory ◽  
Velocity Versus ◽  
Displacement Curve ◽  
Load Displacement ◽  
Corrosion Mechanisms ◽  
Crack Growth Velocity

A technique was developed to obtain the subcritical crack growth velocity in a 4-point bending sample by analyzing the load-displacement curve. This was based on the observation that the compliance of a beam increases as the crack grows. Beam theory was used to analyze the general configuration where two cracks propagated in the opposite directions. A simple equation relating the crack velocity to the load and displacement was established, taking advantage of the fact that the compliance was linearly proportional to the crack lengths; thus the absolute crack length was not important. Two methods of obtaining crack velocity as a function of load were demonstrated. First, by analyzing a load-displacement curve, a corresponding velocity curve was obtained. Second, by changing the displacement rate and measuring the corresponding plateau load, a velocity value was calculated for each plateau load. While the former was capable of obtaining the dependence of crack velocity versus load from a single test, the latter was found to be simpler and more consistent. Applications were made to a CVD SiO2 system. In both cases of crack propagation either inside the SiO2 layer or along its interface with a TiN layer, the crack growth velocity changed with the stress intensity at the crack tip exponentially. As a result, a small crack will grow larger under essentially any tensile stresses typically existing in devices, provided that chemical agents facilitating stress corrosion mechanisms are also present.

scholarly journals Evaluation of Subcritical Crack Growth in Glass Ceramics. Examination by Double Torsion Technique.

1997 ◽  
Vol 63 (607) ◽  
pp. 493-498 ◽  
Author(s):  
Kiyohiko IKEDA ◽  
Takaaki INOTANI ◽  
Koichi KAIZU ◽  
Hisashi IGAKI ◽  
Hiroyosi KIHARA
Keyword(s):  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Glass Ceramics ◽  
Double Torsion

The roles of microstructure and surface energy on subcritical crack growth in glass-ceramics

2020 ◽  
Author(s):  
Pamela Ricco ◽  
Nathália de Carvalho Ramos ◽  
Tiago Moreira Bastos Campos ◽  
Viviane Oliveira Soares ◽  
Mariana de Oliveira Carlos Villas Boas ◽  
...  
Keyword(s):  
Surface Energy ◽  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Glass Ceramics

scholarly journals Effect of environment and polyaxial stress states on subcritical crack growth in glass ceramics.

1990 ◽  
Vol 56 (525) ◽  
pp. 1116-1122
Author(s):  
Kiyohiko IKEDA ◽  
Hisashi IGAKI ◽  
Yoshinobu TANIGAWA ◽  
Koichiro TAGASHIRA
Keyword(s):  
Crack Growth ◽  
Subcritical Crack Growth ◽  
Glass Ceramics ◽  
Stress States
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