Initial Oxidation of a Third-Generation Ni-Based Superalloy Analyzed by in situ Environmental TEM

2019 ◽  
Author(s):  
Yadi Zhai ◽  
Yunsong Zhao ◽  
Xueqiao Li ◽  
Yanhui Chen ◽  
Qingsong Deng ◽  
...  
Keyword(s):  
Third Generation ◽  
Initial Oxidation ◽  
Environmental Tem

scholarly journals 3C-SiC Nanowires In-Situ Modified Carbon/Carbon Composites and Their Effect on Mechanical and Thermal Properties

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 894 ◽  
Author(s):  
Hongjiao Lin ◽  
Hejun Li ◽  
Qingliang Shen ◽  
Xiaohong Shi ◽  
Tao Feng ◽  
...  
Keyword(s):  
Shear Strength ◽  
Thermal Properties ◽  
Sol Gel ◽  
Interlaminar Shear Strength ◽  
Mechanical And Thermal Properties ◽  
Initial Oxidation ◽  
Sic Nanowires ◽  
Out Of Plane ◽  
Interlaminar Shear

An in-situ, catalyst-free method for synthesizing 3C-SiC ceramic nanowires (SiCNWs) inside carbon–carbon (C/C) composites was successfully achieved. Obtained samples in different stages were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman scattering spectroscopy. Results demonstrated that the combination of sol-gel impregnation and carbothermal reduction was an efficient method for in-situ SiCNW synthesis, inside C/C composites. Thermal properties and mechanical behaviors—including out-of-plane and in-plane compressive strengths, as well as interlaminar shear strength (ILLS) of SiCNW modified C/C composites—were investigated. By introducing SiCNWs, the initial oxidation temperature of C/C was increased remarkably. Meanwhile, out-of-plane and in-plane compressive strengths, as well as interlaminar shear strength (ILLS) of C/C composites were increased by 249.3%, 109.2%, and 190.0%, respectively. This significant improvement resulted from simultaneous reinforcement between the fiber/matrix (F/M) and matrix/matrix (M/M) interfaces, based on analysis of the fracture mechanism.

Initial oxidation of Ti–Al intermetallics: an in situ MXPS study

2000 ◽  
Vol 158 (1-2) ◽  
pp. 64-74 ◽  
Author(s):  
J Geng ◽  
G Gantner ◽  
P Oelhafen ◽  
P.K Datta
Keyword(s):  
Initial Oxidation

In-situ Environmental TEM (ETEM) of n-Butane Oxidation: Advances and Challenges in the Catalyst Microstructural Design

2004 ◽  
Vol 10 (S02) ◽  
pp. 38-39 ◽  
Author(s):  
Pratibha L Gai
Keyword(s):  
Butane Oxidation ◽  
Environmental Tem ◽  
Microstructural Design

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

Failure properties of 352 explanted silicone-gel breast implants

1996 ◽  
Vol 4 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Walter Peters ◽  
Dennis Smith ◽  
Stanley Lugowski
Keyword(s):  
First Generation ◽  
Second Generation ◽  
Survival Curve ◽  
Breast Implants ◽  
Thick Wall ◽  
Thin Wall ◽  
Third Generation ◽  
Silicone Gel ◽  
Failure Properties

There have been three generations of silicone-gel breast implants. First generation implants (thick wall – thick gel with Dacron patches) were made from 1963 to 1972. Second generation implants (thin wall-thin gel) were made from 1972 until the mid 1980s. The introduction of third generation implants (stronger wall, low-bleed) was geographically dependent. In Canada, Dow Corning Silastic II implants were introduced in 1986, and Surgitek SCL implants were introduced in 1988. In the present study, a total of 352 silicone-gel breast implants were removed from 239 patients between 1981 and 1995. Their failure properties were dependent upon their generation (year of manufacture) and, for second generation implants, their duration in situ. Of the 352 implants, 20 were first generation, and all were fully intact. Twenty-eight were third generation implants, and 27 were fully intact. Failure properties of the 302 second generation implants were dependent upon their duration of implantation. A survival curve indicated that these implants began to fail (by leaking or rupturing) after four years in situ. By six years, 40% had failed. After 12 years, 95% had failed. Of the 171 second generation implants removed between 1991 and 1995, 77% had failed. The failure properties were similar for the three main manufacturers: Dow Corning, Heyer-Schulte and Surgitek. The failure rate for second generation implants is much higher than was previously believed. This is particularly significant in view of the current difficulty in diagnosing implant failure.

scholarly journals Probing Dynamic Processes of the Initial Stages of Cu(100) Surface Oxidation by in situ Environmental TEM and Multiscale Simulations

2018 ◽  
Vol 24 (S1) ◽  
pp. 262-263 ◽  
Author(s):  
Meng Li ◽  
Matthew T. Curnan ◽  
Hao Chi ◽  
Xinyu Li ◽  
Graeme Henkelman ◽  
...  
Keyword(s):  
Surface Oxidation ◽  
Dynamic Processes ◽  
Multiscale Simulations ◽  
Environmental Tem

In Situ Measurement of the Phase Transformation Behavior of Al2O3 Scale during High-Temperature Oxidation using Synchrotron Radiation

2011 ◽  
Vol 696 ◽  
pp. 63-69 ◽  
Author(s):  
Shigenari Hayashi ◽  
Isao Saeki ◽  
Yoshitaka Nishiyama ◽  
Takashi Doi ◽  
Shoji Kyo ◽  
...  
Keyword(s):  
High Temperature ◽  
Synchrotron Radiation ◽  
High Temperature Oxidation ◽  
Structural Changes ◽  
Lattice Parameter ◽  
Transformation Behavior ◽  
Initial Oxidation ◽  
Temperature Oxidation ◽  
Diffraction Peaks

Very thin Fe-coatings, ~50nm, were found to suppress metastable Al2O3 formation on Fe-50Al and Ni-50Al alloys in our previous study. The authors proposed a mechanism whereby α-Al2O3 precipitates from the Al-saturated Fe2O3, which was formed during initial oxidation, since α-Al2O3 and α-Fe2O3 have isomorphous structures. In order to confirm the proposed mechanism, in-situ measurements were made of structural changes in the oxide scales formed on FeAl with and without Fe coating during heating and subsequent isothermal high temperature oxidation by synchrotron radiation with a two-dimensional X-ray detector. Diffraction peaks from Fe2O3 were initially observed at around 350°C on Fe-coated samples. The lattice parameter of the Fe2O3 initially increased linearly due to thermal expansion, but then rapidly decreased due to the formation of a solid solution of Fe2O3-Al2O3. α-Al2O3 started to appear at around 800°C, but no peaks from metastable Al2O3 were observed. The diffraction peaks from the α-Al2O3 on Fe-coated samples consisted of two distinct peaks, indicating that the α-Al2O3 had two different lattice parameters. These results suggest that the α-Al2O3 was formed not only by precipitation from the Al-saturated Fe2O3, but also by oxidation of Al in the substrate.

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