Characteristics of Fibre-reinforced Ceramic-matrix Composites

3 Characteristics of Fibre-reinforced Ceramic-matrix Composites 

In general the strength of monolithic ceramics decreases significantly at elevated temperatures due to the softening and sliding of a glass phase at the grain 

The equations for monolithic ceramics together with the experimental results of the notched specimen are used to determine the fracture toughness (represented as KIC) of the 3-D C/SiC composites created with the single edge notched beam (SENB) method. Its value is calculated as 20.3 MPa-m1/2, which is much higher than that of monolithic ceramic materials (3 to 5 MPa-m1/2). It should be noted that 

Instrumented Charpy impact tests on unnotched samples are conducted to determine the energy absorbing capability and dynamic fracture behaviour of the C/SiC composites. The dynamic fracture toughness (ak) is calculated using the following equation  

For 3-D C/SiC composite materials the value of ak is 62 kJ-m 2, which could be comparable to that of a super-alloy (ak = 80 160 kJ-m 2). The impact fracture 

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