scholarly journals Crack Evolution and Oxidation Failure Mechanism of a SiC-Ceramic Coating Reactively Sintered on Carbon/Carbon Composites

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7780
Author(s):  
Min Xu ◽  
Lingjun Guo ◽  
Hanhui Wang
Keyword(s):  
Computed Tomography ◽  
Ceramic Coating ◽  
Three Dimensional ◽  
Carbon Composites ◽  
Self Healing ◽  
Internal Damage ◽  
X Ray ◽  
Heating And Cooling ◽  
Sic Ceramic ◽  
X Ray Computed

A SiC ceramic coating was prepared on carbon/carbon composites by pack cementation. The phase composition and microstructure of the coated specimens were characterized using X-ray diffraction instrument and scanning electron microscope. The results showed that the mass-loss percentage of the coated specimen was 9.5% after being oxidized for 20 h. The oxidation failure of the SiC ceramic coating at 1773 K was analysed by non-destructive X-ray computed tomography. The effective self-healing of cracks with widths below 12.7 μm introduced during the coating preparation process and generated while the specimens cooled down from the high oxidation temperature prevented the oxidation of carbon/carbon composites. X-ray computed tomography was used to obtain three-dimensional images revealing internal damage caused by spallation and open holes on the coating. Stress induced by heating and cooling caused the formation, growth and coalescence of cracks, which in turn led to exfoliation of the coating and subsequent failure of oxidation protection.

scholarly journals Three‐dimensional X‐ray‐computed tomography of 3300‐ to 6000‐year‐old Citrullus seeds from Libya and Egypt compared to extant seeds throws doubts on species assignments

2021 ◽  
Author(s):  
Katherine A. Wolcott ◽  
Guillaume Chomicki ◽  
Yannick M. Staedler ◽  
Krystyna Wasylikowa ◽  
Mark Nesbitt ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
X Ray ◽  
X Ray Computed

Use of X-ray computed tomography for studying the desiccation cracking and self-healing of fine soil during drying–wetting paths

2021 ◽  
pp. 106255
Author(s):  
Mohammed Zaidi ◽  
Nasre-Dine Ahfir ◽  
Abdellah Alem ◽  
Said Taibi ◽  
Bouabid El Mansouri ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Self Healing ◽  
X Ray ◽  
Fine Soil ◽  
Desiccation Cracking ◽  
X Ray Computed

Visualizing Fluid Flows With X-Rays

2007 ◽  
Author(s):  
Theodore J. Heindel ◽  
Terrence C. Jensen ◽  
Joseph N. Gray
Keyword(s):  
Computed Tomography ◽  
Flow Visualization ◽  
Three Dimensional ◽  
Fluid Flows ◽  
X Rays ◽  
Radiographic Images ◽  
Optical Access ◽  
X Ray ◽  
X Ray Computed ◽  
Density Map

There are several methods available to visualize fluid flows when one has optical access. However, when optical access is limited to near the boundaries or not available at all, alternative visualization methods are required. This paper will describe flow visualization using an X-ray system that is capable of digital X-ray radiography, digital X-ray stereography, and digital X-ray computed tomography (CT). The unique X-ray flow visualization facility will be briefly described, and then flow visualization of various systems will be shown. Radiographs provide a two-dimensional density map of a three dimensional process or object. Radiographic images of various multiphase flows will be presented. When two X-ray sources and detectors simultaneously acquire images of the same process or object from different orientations, stereographic imaging can be completed; this type of imaging will be demonstrated by trickling water through packed columns and by absorbing water in a porous medium. Finally, local time-averaged phase distributions can be determined from X-ray computed tomography (CT) imaging, and this will be shown by comparing CT images from two different gas-liquid sparged columns.

Three-dimensional analysis of plant structure using high-resolution X-ray computed tomography

2003 ◽  
Vol 8 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Wolfgang H Stuppy ◽  
Jessica A Maisano ◽  
Matthew W Colbert ◽  
Paula J Rudall ◽  
Timothy B Rowe
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Plant Structure ◽  
X Ray ◽  
X Ray Computed

Three dimensional characterization of laser ablation craters using high resolution X-ray computed tomography

2018 ◽  
Vol 139 ◽  
pp. 75-82 ◽  
Author(s):  
A.H. Galmed ◽  
A. du Plessis ◽  
S.G. le Roux ◽  
E. Hartnick ◽  
H. Von Bergmann ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Laser Ablation ◽  
High Resolution ◽  
Three Dimensional ◽  
X Ray ◽  
X Ray Computed

Rapid prototyping for orthopaedic surgery

1998 ◽  
Vol 212 (5) ◽  
pp. 383-393 ◽  
Author(s):  
P Potamianos ◽  
A A Amis ◽  
A J Forester ◽  
M McGurk ◽  
M Bircher
Keyword(s):  
Computed Tomography ◽  
Rapid Prototyping ◽  
Orthopaedic Surgery ◽  
Three Dimensional ◽  
Clear Understanding ◽  
Shoulder Injury ◽  
Physical Relationship ◽  
X Ray ◽  
Joint Pathology ◽  
X Ray Computed

The revision of an orthopaedic procedure can present surgeons with the challenge of a complex reconstructive process. Orthopaedic surgery can also face considerable challenges in cases presenting extensive primary injuries with multiple bone fragmentation, as well as in cases presenting bone deformities. Radiographs are used routinely for orthopaedic surgical planning, yet they provide inadequate information on the precise three-dimensional extent of bone defects. Three-dimensional reconstructions from X-ray computed tomography offer superior visualization but are not portable for consultation or readily available in the operating theatre for guidance during a procedure. A physical model manufactured from X-ray computed tomography data can offer surgeons a clear understanding of complex anatomical detail, by providing an intuitive physical relationship between patient and model. Rapid prototyping was used for the construction of an anatomical model in a case presenting with a complex shoulder injury. The model provided a definitive interpretation of joint pathology and enabled a full assessment of the degree of injury.

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