Assessment of Changes in Microstructure and Hardness of Bearing Steel for Operation at a High Temperature Caused by Short-Term Overheating

AbstractThe paper presented research results of the impact of short-term overheating of samples collected from the outer bearing ring suitable for the operation at elevated temperature installed in the turbine engine on the microstructure and hardness of the material. The samples were annealed at the following temperatures: 500, 600, 700, 800, 900 and 1000°C; and then cooled in still air. Microstructure examinations were conducted under metallographic microscope and transmission electron microscope.

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Real-time cryo-deformation of polypropylene and impact-modified polypropylene in the transmission electron microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150290 ◽

1993 ◽

Vol 51 ◽

pp. 892-893

Author(s):

Robert C. Cieslinski ◽

H. Craig Silvis ◽

Daniel J. Murray

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Failure Mechanisms ◽

Brittle Transition ◽

Molded Part ◽

Transmission Electron ◽

Solvent Cast ◽

The Impact ◽

Annealed Copper ◽

Dynamic Plane

An understanding of the mechanical behavior polymers in the ductile-brittle transition region will result in materials with improved properties. A technique has been developed that allows the realtime observation of dynamic plane stress failure mechanisms in the transmission electron microscope. With the addition of a cryo-tensile stage, this technique has been extented to -173°C, allowing the observation of deformation during the ductile-brittle transition.The technique makes use of an annealed copper cartridge in which a thin section of bulk polymer specimen is bonded and plastically deformed in tension in the TEM using a screw-driven tensile stage. In contrast to previous deformation studies on solvent-cast films, this technique can examine the frozen-in morphology of a molded part.The deformation behavior of polypropylene and polypropylene impact modified with EPDM (ethylene-propylene diene modified) and PE (polyethylene) rubbers were investigated as function of temperature and the molecular weight of the impact modifier.

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A Study of Membrane Impact on Spatial Resolution of Liquid In Situ Transmission Electron Microscope

Microscopy and Microanalysis ◽

10.1017/s143192761901523x ◽

2020 ◽

Vol 26 (1) ◽

pp. 126-133

Author(s):

Ming Li ◽

Ruth Knibbe

Keyword(s):

Electron Microscope ◽

Spatial Resolution ◽

Transmission Electron Microscope ◽

Signal To Noise Ratio ◽

Chromatic Aberration ◽

Membrane Thickness ◽

Additional Material ◽

Transmission Electron ◽

The Impact

AbstractMicrochip technology with electron transparent membranes is a key component for in situ liquid transmission electron microscope (TEM) characterization. The membranes can significantly influence the TEM imaging spatial resolution, not only due to introducing additional material layers but also due to the associated bulging. The membrane bulging is largely defined by the membrane materials, thickness, and short dimension. The impact of the membrane on the spatial resolution, especially the extent of its bulging, was systematically investigated through the impact on the signal-to-noise ratio, chromatic aberration, and beam broadening. The optimization of the membrane parameters is the key component when designing the in situ TEM liquid cell. The optimal membrane thickness of 50 nm was found which balances the impact of membrane bulging and membrane thickness. Beyond this, the short membrane window dimension and the chip nominal spacing should be minimized. However, these two parameters have practical limitations in regards to chip handling.

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Shape stability of chosen thin wood based panels after heating

Annals of WULS, Forestry and Wood Technology ◽

10.5604/01.3001.0013.7742 ◽

2019 ◽

Vol 106 ◽

pp. 85-89

Author(s):

MACIEJ SYDOR ◽

Bartosz Pałubicki

Keyword(s):

High Temperature ◽

Elevated Temperature ◽

Thin Plate ◽

Dimensional Stability ◽

Power Supplies ◽

Short Term ◽

Shape Stability ◽

Short Term Exposure ◽

The Impact

Shape stability of chosen thin wood based panels after heating. Lignocellulose board materials are commonly used for furniture construction. Typically, these are particle boards, fibreboard or plywood with thicknesses from 10 to 20 mm, however, some furniture elements are made of thin boards with a thickness of 3-4 mm (back walls, bottoms of drawers and others). Modern furniture uses built-in components that are a source of heat, such as lamps, power supplies, ovens. Local high temperature may negatively affect the shape stability of thin lignocellulose plates. The aim of the research described in this article was to determine the impact of shortterm exposure to high temperature on the dimensional stability of selected thin plate furniture materials. Four different HDF boards with nominal thicknesses of 3 mm and four different plywood boards with nominal thicknesses of 2 to 4 mm were tested. The test samples were subjected to a short-term exposure to temperatures of up to 250°C. As a result of the tests, it was found that HDF boards are characterized by a much higher shape stability at elevated temperature than boards made of plywood.

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Analysis of Spherical Carbides Formed in Chromium Added Hypereutectoid Bearing Steels

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.4866 ◽

2007 ◽

Vol 539-543 ◽

pp. 4866-4871 ◽

Cited By ~ 1

Author(s):

Atsushi Yamamoto ◽

Katsuhiko Inoue ◽

Harushige Tsubakino

Keyword(s):

Electron Microscope ◽

Synchrotron Radiation ◽

Low Temperature ◽

Transmission Electron Microscope ◽

Bearing Steel ◽

Bearing Steels ◽

Transmission Electron ◽

Synchrotron Radiation Diffraction ◽

M23c6 Type ◽

Means Of Transmission

Microstructures in a bearing steel, JIS SUJ2, have been observed and analyzed in detail by means of transmission electron microscope and synchrotron radiation diffraction in SPring-8. Spherodized carbides in the steel are generally recognized as spherical cementite particles, but some of them have been clearly shown to be M23C6 type of carbide in this study. The shapes and sizes of these two types of carbides are similar to each other. On the martensitic matrix of the steel, it is believed to be stable at relatively low temperature, but it is also shown to be decomposed to form cementite by prolonged aging at 383 K, which provides a reason for decrease in hardness in standard hardness blocks, previously reported by the authors.

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Transmission electron microscope observation of dark‐spot defects in InGaAsP/InP double‐heterostructure light‐emitting diodes aged at high temperature

Applied Physics Letters ◽

10.1063/1.91469 ◽

1980 ◽

Vol 36 (4) ◽

pp. 300-301 ◽

Cited By ~ 26

Author(s):

Osamu Ueda ◽

Shigenobu Yamakoshi ◽

Satoshi Komiya ◽

Kenzo Akita ◽

Toyoshi Yamaoka

Keyword(s):

Electron Microscope ◽

High Temperature ◽

Transmission Electron Microscope ◽

Light Emitting Diodes ◽

Dark Spot ◽

Electron Microscope Observation ◽

Light Emitting ◽

Double Heterostructure ◽

Transmission Electron Microscope Observation ◽

Transmission Electron

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A Biomimetic Method of Hydroxyapatite Powders Synthesized in Simulated Body Fluid

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.297-300.1371 ◽

2005 ◽

Vol 297-300 ◽

pp. 1371-1375

Author(s):

Feng Wang ◽

Mu Sen Li

Keyword(s):

Electron Microscope ◽

High Temperature ◽

Simulated Body Fluid ◽

Transmission Electron Microscope ◽

Body Fluid ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Infra Red ◽

Biomimetic Method

Hydroxyapatite (HA) powders were directly synthesized in simulated body fluid (SBF) at 37°C, without the need for high-temperature calcified. These powders were found to contain trace amount of CO32-, Cl-, Na+ and K+ impurities, originated from the of SBF solutions during their deposition. The characterizations of the synthesized HA powders were performed by X-ray diffraction (XRD), Fourier-transformed infra-red spectroscopy (FTIR) and Transmission electron microscope (TEM). The experimental results showed that the HA synthesized by the SBF route might be more close to that human bone in structure and compositions. Furthermore, the processes flow for HA synthesis was optimized and the synthesized mechanism was also discussed.

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Intercalation of Poly-acrylonitrile (PAN) into carbon nanotubes

The Journal of Undergraduate Research at the University of Illinois at Chicago ◽

10.5210/jur.v1i1.7452 ◽

2007 ◽

Vol 1 (1) ◽

Author(s):

V. Chan ◽

K. Sun ◽

A. Yarin ◽

C.M. Megaridis

Keyword(s):

Carbon Nanotubes ◽

Electron Microscope ◽

High Temperature ◽

Diffusion Process ◽

Transmission Electron Microscope ◽

Average Diameter ◽

Carbonization Process ◽

Intercalation Process ◽

Transmission Electron ◽

Poly Acrylonitrile

The primary goal of this work is to fill 200 nm average diameter CVD Carbon nanotubes (CNTs) with Poly-acrylonitrile (PAN) - a carbonizable polymer - with the diffusion process reported by Bazilevsky et al. and to control the thickness and structure of the PAN inside the CNTs. Transmission electron microscope (TEM) was used as a tool to monitor the morphology of polymer filled nanotubes. TEM images of CNTs that were filled using five different PAN concentrations of the PAN/DMF solution - 0.1, 0.5, 1, 2, and 5 wt% - demonstrated that the intercalation process is independent of the initial PAN concentration in solution. Furthermore, a DMF rinse process was used to remove polymer that was clinging to the outer walls of the CNTs, allowing clearer visual of the PAN structure in the interior of the CNTs. Finally, TEM images of filled CNTs taken through a carbonization process demonstrated that the CNT samples were able to survive the high temperature, with some damage to the CNT walls.

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