scholarly journals Microstructure and mechanical properties of 3D Cf/SiBCN composites fabricated by polymer infiltration and pyrolysis

2020 ◽  
Author(s):  
Bowen Chen ◽  
Qi Ding ◽  
Dewei Ni ◽  
Hongda Wang ◽  
Yusheng Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Three Dimensional ◽  
Cross Linking ◽  
Ceramic Yield ◽  
X Ray ◽  
3D Microstructure ◽  
Crosslinking Process ◽  
X Ray Computed ◽  
Polymer Infiltration

AbstractIn this work, three-dimensional (3D) Cf/SiBCN composites were fabricated by polymer infiltration and pyrolysis (PIP) with poly(methylvinyl)borosilazane as SiBCN precursor. The 3D microstructure evolution process of the composites was investigated by an advanced X-ray computed tomography (XCT). The effect of dicumyl peroxide (DCP) initiator addition on the crosslinking process, microstructure evolution, and mechanical properties of the composites were uncovered. With the addition of a DCP initiator, the liquid precursor can cross-linking to solid-state at 120 °C. Moreover, DCP addition decreases the release of small molecule gas during pyrolysis, leading to an improved ceramic yield 4.67 times higher than that without DCP addition. After 7 PIP cycles, density and open porosity of the final Cf/SiBCN composite with DCP addition are 1.73 g·cm−3 and ∼10%, respectively, which are 143.0% higher and 30.3% lower compared with the composites without DCP addition. As a result, the flexural strength and elastic modulus of Cf/SiBCN composites with DCP addition (371 MPa and 31 GPa) are 1.74 and 1.60 times higher than that without DCP addition (213 MPa and 19.4 GPa), respectively.

scholarly journals Microstructure and mechanical properties of 3D Cf/SiBCN composites fabricated by polymer infiltration and pyrolysis

2020 ◽  
Author(s):  
Bowen Chen ◽  
Qi Ding ◽  
De-Wei Ni ◽  
Hongda Wang ◽  
Yusheng Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Cross Link ◽  
Ceramic Yield ◽  
Liquid Precursor ◽  
X Ray ◽  
3D Microstructure ◽  
Crosslinking Process ◽  
X Ray Computed ◽  
Polymer Infiltration

Abstract In this work, 3D Cf/SiBCN composites were fabricated by polymer infiltration and pyrolysis (PIP) with poly(methylvinyl)borosilazane as SiBCN precursor. The 3D microstructure evolution process of the composites was investigated by an advanced x-ray computed tomography (XCT). The effect of dicumyl peroxide (DCP) initiator addition on the crosslinking process, microstructure evolution and mechanical properties of the composites were uncovered. With the addition of DCP initiator, the liquid precursor can cross-link to solid-state at 120 °C. Moreover, DCP addition decreases the release of small molecule gas during pyrolysis, leading to an improved ceramic yield 4.67 times higher than that without DCP addition. After 7 PIP cycles, density and open porosity of the final Cf/SiBCN composite with DCP addition are 1.73 g·cm-3 and ~10%, respectively, which are 143.0% higher and 30.3% lower compared with the composite without DCP addition. As a result, the flexural strength and elastic modulus of Cf/SiBCN composites with DCP addition (371 MPa and 31 GPa) are 1.74 and 1.60 times higher than that without DCP addition (213 MPa and 19.4 GPa).

scholarly journals Microstructure and mechanical properties of 3D Cf/SiBCN composites fabricated by polymer infiltration and pyrolysis

2020 ◽  
Author(s):  
Bowen Chen ◽  
Qi Ding ◽  
De-Wei Ni ◽  
Hongda Wang ◽  
Yusheng Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Cross Link ◽  
Ceramic Yield ◽  
Liquid Precursor ◽  
X Ray ◽  
3D Microstructure ◽  
Crosslinking Process ◽  
X Ray Computed ◽  
Polymer Infiltration

Abstract In this work, 3D C f /SiBCN composites were fabricated by polymer infiltration and pyrolysis (PIP) with poly(methylvinyl)borosilazane as SiBCN precursor. The 3D microstructure evolution process of the composites was investigated by an advanced x-ray computed tomography (XCT). The effect of dicumyl peroxide (DCP) initiator addition on the crosslinking process, microstructure evolution and mechanical properties of the composites were uncovered. With the addition of DCP initiator, the liquid precursor can cross-link to solid-state at 120 °C. Moreover, DCP addition decreases the release of small molecule gas during pyrolysis, leading to an improved ceramic yield 4.67 times higher than that without DCP addition. After 7 PIP cycles, density and open porosity of the final Cf/SiBCN composite with DCP addition are 1.73 g·cm -3 and ~10%, respectively, which are 143.0% higher and 30.3% lower compared with the composites without DCP addition. As a result, the flexural strength and elastic modulus of Cf/SiBCN composites with DCP addition (371 MPa and 31 GPa) are 1.74 and 1.60 times higher than that without DCP addition (213 MPa and 19.4 GPa).

scholarly journals Three-Dimensional (3D) Microstructure-Based Modeling of a Thermally-Aged Cast Duplex Stainless Steel Based on X-ray Microtomography, Nanoindentation and Micropillar Compression

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 688
Author(s):  
Qingdong Zhang ◽  
Kai Zhu ◽  
Arun Sundar S. Singaravelu ◽  
Weizhao Sun ◽  
Tao Jing ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Three Dimensional ◽  
Compression Tests ◽  
Element Analysis ◽  
X Ray ◽  
3D Microstructure ◽  
Individual Phase ◽  
Micropillar Compression

Finite element analysis was conducted on a thermally-aged cast duplex stainless steel based on the true three-dimensional (3D) microstructure obtained from X-ray microtomography experiments and using the constitutive behavior of each individual phase extracted from nanoindentation on single-crystal and bicrystal micropillar compression tests. The evolution of the phase morphology, the mechanical properties and the boundary deformation behavior during the aging process are highlighted. Quantitative analysis in terms of the distribution and evolution of the stress and strain in both the as received and aged conditions was performed. The experimental results show that aging at an intermediate temperature has a negligible influence on the morphology of the two phases in cast duplex stainless steel (CDSS). Results from simulations reveal that the mechanical behavior of this material were seriously affected by the microstructure and the mechanical properties of the individual phase and the necking deformation tend to form in the area with less large ferrite grains after aging. In addition, stress localization tends to form at the austenite/ferrite interface, in the narrow region of ferrite grains and in the small ferrite grains.

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

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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