Fracture behaviour of microcrack-free alumina–aluminium titanate ceramics with second phase nanoparticles at alumina grain boundaries

Bueno, Salvador; Berger, Marie‐Hélène; Moreno, Rodrigo; Baudı́n, Carmen

doi:10.1016/j.jeurceramsoc.2008.01.017

Cited by 46 publications

(47 citation statements)

References 51 publications

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“…Figure 7 shows a load-displacement curve registered during the experiment on a material where toughening mechanisms contribute to its fracture (35). Initially, the material behaves in a linear manner until it reaches a load value from which point nonlinear phenomena occur; the relative size of the linear and non-linear portions of the curves depend on the properties of the material and the toughening mechanisms in operation.…”

Section: Toughening Mechanismsmentioning

confidence: 99%

“…Although work of fracture has been successfully used to describe the fracture of refractories (58), its use in advanced ceramic materials has been much more limited (35,63,65,68), due to the experimental difficulty involved in obtaining stable tests in low-toughness materials. Thus, even in the case of such widely studied and characterized materials as dense single-phase aluminas, the majority of the work of fracture experiments described in scientific literature refers to materials with average grain sizes of over 5 µm (69)(70).…”

Section: Work Of Fracturementioning

confidence: 99%

“…Recently (35) an alumina material with a smaller average grain size (3.5µm) was characterized, giving a work of fracture value of 10J/m 2 . Although this value is significantly lower than the value of materials with coarser microstructures (35,70) (e.g: 20J/m 2 for an alumina with an average size of 5.5µm (35)), it is still much higher than the value (≅6 J/m 2 ) determined for the preferred cleavage plane in alumina single-crystals (71), due to the above mentioned processes associated with the fracture of polycrystals.…”

Section: Work Of Fracturementioning

confidence: 99%

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Comportamiento mecánico de materiales cerámicos estructurales

Bueno¹,

Baudı́n²

2007

Bol. Soc. Esp. Ceram. Vidr.

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The use of ceramic materials in structural applications is limited by the lack of reliability associated with brittle fracture behaviour. In order to extend the structural use of ceramics, the design of microstructures which exhibit flaw tolerance due to toughening mechanisms which produce an increase in crack growth resistance during crack propagation has been proposed. This work is a review of the mechanical behaviour of structural ceramic materials and its characterisation. Firstly, the basic brittle fracture parameters and the statistical criteria to determine the probability of exceeding the safety factors demanded for a particular application are analysed. Then, the toughening mechanisms which can be developed in the materials through microstructural design as well as the mechanical characterisation of toughened ceramics are discussed. The experimental values of linear elastic fracture toughness parameters (critical stress intensity factor, K IC , and critical energy release rate, G IC ) are not intrinsic properties for toughened materials and depend on crack length and the loading system. In this work, the different mechanical parameters proposed to characterise such materials are reviewed. The following fracture parameters are analysed: work of fracture (γ WOF ), critical J-integral value (J IC ) and R-curve. For the determination, stable fracture tests are proposed in order to ensure that the energy provided during the test is no more than the necessary one for crack propagation.Keywords: Microstructure, Strength, Weibull modulus, Fracture toughness, Toughening mechanisms. Comportamiento mecánico de materiales cerámicos estructuralesEl uso de los materiales cerámicos en aplicaciones estructurales está limitado por la falta de fiabilidad asociada a su comportamiento frágil durante la fractura. Para extender su aplicación se ha propuesto el diseño de microestructuras que presenten tolerancia a los defectos debido a la actuación de mecanismos de refuerzo. Este trabajo es una puesta al día sobre el estudio del comportamiento mecánico de los materiales cerámicos estructurales y su caracterización. En primer lugar, se revisan los parámetros de fractura utilizados para caracterizar materiales frágiles y los criterios de control estadístico que permiten determinar la probabilidad de que se sobrepasen los factores de seguridad exigidos en cada aplicación. A continuación, se discuten los mecanismos de refuerzo que se pueden desarrollar en los materiales cerámicos a través del diseño microestructural. En los materiales cerámicos en los que la actuación de mecanismos de refuerzo conduce a un comportamiento significativamente distinto del puramente frágil, los parámetros derivados del tratamiento lineal elástico (factor crítico de intensidad de tensiones, K IC , y tasa crítica de liberación de energía, G IC ), determinados experimentalmente, dejan de ser propiedades intrínsecas del material, independientes del tamaño de grieta y el sistema de carga. El presente trabajo revisa los parámetros mecánicos propuestos para...

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Section: Toughening Mechanismsmentioning

confidence: 99%

Section: Work Of Fracturementioning

confidence: 99%

Section: Work Of Fracturementioning

confidence: 99%

See 1 more Smart Citation

Comportamiento mecánico de materiales cerámicos estructurales

Bueno¹,

Baudı́n²

2007

Bol. Soc. Esp. Ceram. Vidr.

Self Cite

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“…Also, AT is a suitable additive as a second phase that can improve the thermal and mechanical properties of ceramic matrix composites [5]. For example, some researchers have shown that the addition of AT improves the fracture toughness of Al2O3 (A) due to the enhancement of the local residual stresses 3 induced by the large mismatch of thermal expansion coefficient between A and AT [5][6][7][8]. It was also observed that the incorporation of Al2TiO5 in an Al2O3 matrix resulted in better flaw-tolerance properties [6,7] while maintaining the structural integrity.…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies have shown that colloidal processing allows dense, homogeneous A/AT materials to be obtained by reaction sintering of green bodies produced by slip casting of suspensions with controlled mixtures of alumina and titania. However, high temperatures (>1450 ºC) and long processing times (>18h) are required to obtain such dense materials (~97%) with good mechanical properties (230 MPa) by conventional sintering process [5,14,15]. In this sense, the selection of suitable raw materials and adequate green processing techniques is essential to obtain homogeneous, defect-free materials but also the correct choice of the sintering method is crucial to obtain A/AT composites with improved properties.…”

Section: Introductionmentioning

confidence: 99%