scholarly journals In situ observation of the deformation and fracture of an alumina-alumina ceramic-matrix composite at elevated temperature using x-ray computed tomography

2021 ◽  
Vol 41 (7) ◽  
pp. 4217-4230
Author(s):  
Talha J. Pirzada ◽  
Dong Liu ◽  
Jon Ell ◽  
Harold Barnard ◽  
Ivo Šulák ◽  
...  
2019 ◽  
Vol 25 (3) ◽  
pp. 583-591 ◽  
Author(s):  
John Thornton ◽  
Benedicta D. Arhatari ◽  
Mitchell Sesso ◽  
Chris Wood ◽  
Matthew Zonneveldt ◽  
...  

AbstractIn this study, we have examined ceramic matrix composites with silicon carbide fibers in a melt-infiltrated silicon carbide matrix (SiC/SiC). We subjected samples to tensile loads while collecting micro X-ray computed tomography images. The results showed the expected crack slowing mechanisms and lower resistance to crack propagation where the fibers ran parallel and perpendicular to the applied load respectively. Cracking was shown to initiate not only from the surface but also from silicon inclusions. Post heat-treated samples showed longer fiber pull-out than the pristine samples, which was incompatible with previously proposed mechanisms. Evidence for oxidation was identified and new mechanisms based on oxidation or an oxidation assisted boron nitride phase transformation was therefore proposed to explain the long pull-out. The role of oxidation emphasizes the necessity of applying oxidation resistant coatings on SiC/SiC.


Author(s):  
M. R. Bache ◽  
P. I. Nicholson ◽  
E. Williams

The use of X-ray computed tomography (XCT) for detecting sub-critical damage and ultimate failure mechanisms in a ceramic matrix composite is demonstrated. To this end, an initial XCT investigation of a CMC sample, using a commercially available in-situ mechanical loading rig, is presented. As an important step toward a better understanding of the mechanical behaviour of these materials, in-situ XCT inspection was performed on a macroscopic scaled test coupon, i.e. sampling a significant number of fibre bundles, whilst the material was subjected to monotonic tensile load. The observation of inherent processing artefacts, and the tracking of resultant damage in the structure of CMCs, was demonstrated, supported by post test inspections using optical and scanning electron microscopy. Further consideration is given to the requirements for developing XCT systems for in-situ inspection of CMC materials.


2019 ◽  
Vol 236 ◽  
pp. 128-130 ◽  
Author(s):  
Peter Wagner ◽  
Oliver Schwarzhaupt ◽  
Michael May

2018 ◽  
Vol 127 (2) ◽  
pp. 371-389 ◽  
Author(s):  
Tyler Oesch ◽  
Frank Weise ◽  
Dietmar Meinel ◽  
Christian Gollwitzer

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