scholarly journals Water-Jet Erosion of Grade-A Ship Steel: Experimental Research

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yupeng Cao ◽  
Yue Zhang ◽  
Weidong Shi ◽  
Hua Lu ◽  
Linwei Tan ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Central Area ◽  
Water Jet ◽  
Dynamic Strain ◽  
Material Surface ◽  
Transmission Electron ◽  
Peripheral Area ◽  
Erosion Test ◽  
The Impact ◽  
Strain Signal

A water-jet erosion test was carried out on grade-A ship steel to study the interaction and erosion mechanism of the water jet on the steel surface. When the water jet impacted, a STSS-1 stress-detection module was used to collect the dynamic strain signal on the rear of the ship’s plate, and a scanning electron microscope, transmission electron microscope, X-ray diffractometer, and other equipment were used to analyze the microstructure and phase of the grade-A ship steel before impact. The surface morphology of the material after impact was studied and analyzed. The impact stress of the water jet on the grade-A steel was an alternating stress, and the jet pressure decayed in the radial direction. The material surface was fatigued under the action of the jet alternating stress. After the water-jet erosion, the central area of the grade-A steel was dominated by an elongated cementite hard phase, and the peripheral area had a pearlite structure. A model for the jet erosion and peeling of grade-A ship steel was established to clarify the mechanism of erosion by the water jet.

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

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.

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

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.

Influence of Direct Lamellarizing and Tempering on Microstructure and Properties of F550 Ship Plate Steel

2013 ◽  
Vol 773 ◽  
pp. 391-396
Author(s):  
Xiao Lin Li ◽  
Qing Wu Cai ◽  
Wei Yu
Keyword(s):  
Electron Microscope ◽  
Impact Energy ◽  
Bainitic Ferrite ◽  
Optical Microscope ◽  
Cleavage Crack ◽  
Plate Steel ◽  
Microstructure And Properties ◽  
Transmission Electron ◽  
Austenite Grains ◽  
The Impact

The effects of quenching at 820 °C 850 °C 940 °C and tempering at 600 °C on microstructure and properties of F550 ship plate steel were studied by optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and other experimental methods. The results show that the highest value of the impact energy at-80 °C is 240 J when the steel is quenched at 850 °C and tempered at 600 °C. A full graumber of martensite-austenite (M-A) constituents which distribute in the shape of point-liner or gather among the grains, is larger compared with lamellarizing and tempering. Although the strength of the steel is higher, the value of the impact energy at-80 °C is lower and unstable. After intercritical quenching, the presence of minor ferrite and austenite grains refined could also be helpful to improve the low temperature toughness. Because polygonal ferrite (QF) is small and distributes uniformly between bainitic ferrite lathes acting as beneficial barriers to cleavage crack propagation.

Microcraters in Lunar Samples

1970 ◽  
Vol 28 ◽  
pp. 22-23 ◽  
Author(s):  
David S. McKay
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Central Area ◽  
Type I ◽  
Small Glass ◽  
Rock Mineral ◽  
Lunar Samples ◽  
The Impact ◽  
Scanning Electron

Introduction. Samples of rock, mineral, and glass fragments returned by Apollo 11 and 12 contain a variety of microcraters which were formed by the impacts of small projectiles. The craters are especially prominent in some of the small glass spherules and related forms.Crater types. It is possible to classify these microcraters on the basis of morphology as seen by the scanning electron microscope. Type I microcraters (Figure 1) show the following characteristics:A. A glassy central area is present which has been melted by the impact. This glass is primarily material from the target but may also contain melted projectile material. The central area is normally very smooth and may or may not have a smooth raised lip.

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

2020 ◽  
Vol 50 (4) ◽  
pp. 89-110
Author(s):  
Krzysztof Łęczycki ◽  
Sebastian Gronek
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Elevated Temperature ◽  
Transmission Electron Microscope ◽  
Bearing Steel ◽  
Short Term ◽  
Turbine Engine ◽  
Bearing Ring ◽  
Transmission Electron ◽  
The Impact

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.

scholarly journals Morphology Evolution and Rheological Behaviors of PP/SR Thermoplastic Vulcanizate

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 175 ◽  
Author(s):  
Qiang Wu ◽  
Jiafeng Fang ◽  
Minghuan Zheng ◽  
Yan Luo ◽  
Xu Wang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Complex Viscosity ◽  
Mechanical Analysis ◽  
Dynamic Strain ◽  
Hot Press ◽  
Dynamic Vulcanization ◽  
Shear Rates ◽  
High Shear Rates ◽  
Transmission Electron ◽  
Rubber Aggregates

The thermoplastic vulcanizates (TPVs) of polypropylene (PP)/silicone rubber (SR) were prepared by dynamic vulcanization (DV) technology. The mixing torque, morphology, viscoelasticity, and creep response of PP/SR TPVs were investigated by torque rheometer, scanning electron microscope (SEM), transmission electron microscope (TEM), rotational rheometer, and dynamic mechanical analysis (DMA). A mixing-torque study showed that torque change and dynamic-vulcanization time increased with SR content increasing in the DV process, but DV rate was independent of SR content. TEM images indicated that the phase inversion of PP/SR-60 TPV from bicontinuous to a sea–island structure took place in the DV process, and a hot press would break the rubber aggregates and shrink a large SR phase. Dynamic-strain measurement demonstrated that PP/SR TPVs exhibit a distinct “Payne effect”, which can be attributed to the destruction and reconstruction of SR physical networks. Complex viscosity indicated that SR content did not affect the processability of PP/SR TPVs at high shear rates. Furthermore, the creep deformation and recovery of PP/SR TPVs at solid and melt states were studied, respectively.

Improvements in the X-Ray Analytical Capabilities of a Scanning Transmission Electron Microscope by Spherical-Aberration Correction

2006 ◽  
Vol 12 (6) ◽  
pp. 515-526 ◽  
Author(s):  
M. Watanabe ◽  
D.W. Ackland ◽  
A. Burrows ◽  
C.J. Kiely ◽  
D.B. Williams ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Spherical Aberration ◽  
Scanning Transmission Electron Microscope ◽  
Analytical Sensitivity ◽  
X Ray ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Impact

A Nion spherical-aberration (Cs) corrector was recently installed on Lehigh University's 300-keV cold field-emission gun (FEG) Vacuum Generators HB 603 dedicated scanning transmission electron microscope (STEM), optimized for X-ray analysis of thin specimens. In this article, the impact of the Cs-corrector on X-ray analysis is theoretically evaluated, in terms of expected improvements in spatial resolution and analytical sensitivity, and the calculations are compared with initial experimental results. Finally, the possibilities of atomic-column X-ray analysis in a Cs-corrected STEM are discussed.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Surface Structure of the Spores of Glugea Weissenbergi

1969 ◽  
Vol 27 ◽  
pp. 238-239
Author(s):  
Sanford H. Vernick ◽  
Anastasios Tousimis ◽  
Victor Sprague
Keyword(s):  
Electron Microscope ◽  
Surface Structure ◽  
Transmission Electron Microscope ◽  
Mature Spore ◽  
Spore Surface ◽  
Sectioned Material ◽  
Transmission Electron ◽  
Surface Detail

Recent electron microscope studies have greatly expanded our knowledge of the structure of the Microsporida, particularly of the developing and mature spore. Since these studies involved mainly sectioned material, they have revealed much internal detail of the spores but relatively little surface detail. This report concerns observations on the spore surface by means of the transmission electron microscope.

The High Resolution Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 316-317
Author(s):  
A. V. Crewe
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Vacuum ◽  
Scanning Transmission Electron Microscope ◽  
Ultra High Vacuum ◽  
Resolving Power ◽  
Imaging Characteristics ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Moment

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.

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