In-Situ Observation of Clay Minerals Hydrated and Intercalated With Liquid Chemicals Using Film-Sealed Environmental Cell

1980 ◽  
Vol 38 ◽  
pp. 208-209 ◽  
Author(s):  
K. Fukushima ◽  
N. Kohyama ◽  
A. Fukami
Keyword(s):  
Carbon Film ◽  
Resolving Power ◽  
In Situ Observation ◽  
Interlayer Water ◽  
Saturated Water ◽  
Structure Changes ◽  
Environmental Cell ◽  
Gas Layer ◽  
20 Nm

A film-sealed high resolution environmental cell(E.C) for observing hydrated materials had been developed by us(l). Main specification of the E.C. is as follows: 1) Accelerated voltage; 100 kV. 2) Gas in the E.C.; saturated water vapour with carrier gas of 50 Torr. 3) Thickness of gas layer; 50 μm. 4) Sealing film; evaporated carbon film(20 nm thick) with plastic microgrid. 5) Resolving power; 1 nm. 6) Transmittance of electron beam; 60% at 100 kV. The E.C. had been successfully applied to the study of hydrated halloysite(2) (3). Kaolin minerals have no interlayer water and are basically non-expandable but form intercalation compounds with some specific chemicals such as hydrazine, formamide and etc. Because of these compounds being mostly changed in vacuum, we tried to reveal the structure changes between in wet air and in vacuum of kaolin minerals intercalated with hydrazine and of hydrated state of montmori1lonite using the E.C. developed by us.

scholarly journals Preparation, Characterization and Tribological Properties of Diamond-Like Carbon Film on AZ31 Magnesium Alloy

2019 ◽  
Vol 804 ◽  
pp. 69-74
Author(s):  
Bei Bei Han ◽  
Dong Ying Ju ◽  
Susumu Sato ◽  
Hui Jun Zhao
Keyword(s):  
Tribological Properties ◽  
Gas Flow ◽  
Carbon Film ◽  
Observation System ◽  
In Situ Observation ◽  
Force Measurements ◽  
Maximum Hardness ◽  
Low Friction ◽  
Dlc Coatings

In this study, DLC films were deposited using IBED with various CH4/H2 ratio, gas flow rates and accelerating voltages. The composition and mechanical properties of the DLC coatings were characterized using SEM, Raman spectroscopy and nanoindentor. The tribological properties of the coating were also investigated using a frictional surface microscope with an in situ observation system and friction force measurements. The DLC films were characterized by a lower ID/IG, higher hardness, and improved tribological properties when deposited at a lower accelerating voltage (6 kV). At the CH4/H2 ratio of 1:99 and 6 sccm/6 kV, minimum ID/IG values of 0.62, relatively low friction coefficient of 0.12 , and a maximum hardness of 4056 HV were attained respectively.

scholarly journals In situ observation of structural alteration process of filmy quenched carbonaceous composite

2008 ◽  
Vol 4 (S251) ◽  
pp. 433-434
Author(s):  
Akihito Kumamoto ◽  
Yuki Kimura ◽  
Chihiro Kaito ◽  
Setsuko Wada
Keyword(s):  
Electron Microscopy ◽  
Carbon Film ◽  
Film Structure ◽  
Structural Alteration ◽  
In Situ Observation ◽  
Thermal Alteration ◽  
Amorphous Carbon Film ◽  
Alteration Process ◽  
Transmission Electron

AbstractThe thermal alteration process of filmy quenched carbonaceous composite (filmy QCC) has been studied in situ by high-resolution transmission electron microscopy (HRTEM). HRTEM images of the as-prepared filmy QCC showed the typical amorphous carbon film structure. By heating above 300 °C, the structural alteration takes place. Curled graphene structure started to appear at 300 °C. Distorted onion-like structure similar to dark QCC appeared above 500 to 700 °C. The distorted onion-like structure that appears at 700 °C after heating for 30 minutes also appeared by heating at 450 °C for 2 hours.

In-Situ Observation and Mechanical Criterion on Interface Cracking in Nano-Components

2012 ◽  
Vol 1415 ◽  
Author(s):  
T. Kitamura ◽  
T. Sumigawa
Keyword(s):  
Mechanical Property ◽  
Fatigue Behavior ◽  
In Situ Observation ◽  
Displacement Curve ◽  
Si Substrate ◽  
Nano Scale ◽  
Cu Film ◽  
20 Nm ◽  
Interface Edge

ABSTRACTWe have investigated the criterion of interfacial crack initiation in nanometer-scale components (nano-components) by means of a loading facility built in a transmission electron microscope (TEM). Three types of experiments are conducted in this project. (1) In order to clarify the applicability of conventional continuum mechanics to the nano-components, we prepare cantilever specimens with different size, which introduce different stress fields, containing an interface between a 20 nm-thick copper (Cu) thin film and a silicon (Si) substrate. These demonstrate the validity of the “stress” criterion even for the nano-scale fracture. (2) In order to examine the effect of microscopic structure on the mechanical property, we fabricate a bending specimen in the nano-scale with thin Cu bi-crystal (the thickness of about 100 nm) formed on Si substrate, of which understructure can be observed in situ by means of a TEM during the mechanical experiment. The initial plastic deformation takes place near the interface edge in a grain with a high critical resolved shear stress and expands preferentially in the grain. Then, the plasticity appears near the between Cu grain boundary and Cu/Si interface, and this development brings about the interfacial cracking from the junction. These indicate the governing influence of understructure on the mechanical property in the nano-components. (3) In order to investigate the fatigue behavior of metal in a nano-component, a cyclic bending experiment is carried out using nano-cantilever specimens with a 20 nm-thick Cu constrained by highly rigid materials (Si and SiN). The high strain region is in the size of 20-40 nm near the interface edge. The specimen breaks along the Cu/Si interface before the maximum load under the fatigue loading. The load-displacement curve shows nonlinear behavior and a distinct hysteresis loop, indicating plasticity in the Cu film. Reverse yielding appearing after the 2nd cycle suggests the development of a cyclic substructure in the Cu film. These indicate that the crack is caused by characteristic understructure owing to fatigue cycles.

In-situ TEM Observation for Reaction of LiH with NH3 by Means of Environmental Cell

2009 ◽  
Vol 1216 ◽  
Author(s):  
Hiroko Hirasawa ◽  
Shigehito Isobe ◽  
Yongming Wang ◽  
Hikaru Yamamoto ◽  
Hiroki Miyaoka ◽  
...  
Keyword(s):  
Volume Expansion ◽  
In Situ Tem ◽  
In Situ Observation ◽  
Light Weight ◽  
Solid Reaction ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Environmental Cell ◽  
Tem Transmission Electron Microscopy

AbstractIn-situ observation of the reaction between light weight hydride LiH and NH3 gas was performed by means of TEM (Transmission Electron Microscopy) with an environmental cell. This environmental cell was designed for the observation of the gas-solid reaction under 0 ∼ 0.2 MPa gas atmosphere at 20 ∼ 150 °C. It has been confirmed a volume expansion and generation of LiNH2, that is the reaction between LiH and NH3. Moreover, it was revealed that LiNH2 was generated at the surface of LiH particle at first process of the reactions.

In Situ Observation of Nanocrystal Formation Via Dehydroxylation

2001 ◽  
Vol 7 (S2) ◽  
pp. 438-439
Author(s):  
Renu Sharma ◽  
M. J. McKelvy ◽  
Hamdallah Bearat ◽  
Andrew V.G. Chizmeshya ◽  
R.W. Carpenter
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
High Vacuum ◽  
Atomic Level ◽  
Metal Particles ◽  
In Situ Observation ◽  
Fine Powders ◽  
Environmental Cell ◽  
Nanocrystal Formation

Recently, a promising new route to prepare nano phase composites with fine transition metal particles (2 - 50nm) has been proposed via dehydroxylation and dehydration process. Thermal and mechanical dehydroxylation process has also been used to form ultra fine powders of NiO-Ni(OH). We have found a substantially increased carbonation rate at room temperature (RT) for partially dehydroxylated brucite (Mg(OH)2) single crystal fragments. BET measurements confirm the increase in the surface area of partially dehydroxylated (90%) single-crystal Mg(OH)2 fragments, which directly contributes to the increase in carbonation reactivity. As dehydroxylation proceeds rapidly in a TEM column, due to high vacuum and electron beam effects, the atomic level nature of the process has not been understood until recently.6 We have observed the development of nanocrystals during in situdehydroxylation of Mg(OH)2.Experiments were performed using a PHILIPS-430 electron microscope operated at 300KV, fitted with a differentially pumped environmental-cell (E-cell) and a Gatan Imaging Filter (GIF).

In-Situ Observation of Deformation Processes by OIM

1997 ◽  
Vol 3 (S2) ◽  
pp. 567-568
Author(s):  
Hasso Weiland
Keyword(s):  
Single Crystals ◽  
Mechanical Response ◽  
Thermal Exposure ◽  
Structure Evolution ◽  
In Situ Observation ◽  
Recrystallization Behavior ◽  
X Ray ◽  
Structure Changes ◽  
Deformation Processes

The thermo-mechanical response of single crystals has been studied in detail since the discovery of X-ray and electron diffraction. While an extensive knowledge exists on the effect of crystallographic orientation on deformation and recrystallization behavior of single crystals, the thermo-mechanical response of grains of different orientations embedded in a polycrystalline matrix are not well understood. With the emergence of microstructure based models predicting the structure evolution during deformation or recrystallization, data validating the predicted structure changes are essential. This requires to study the evolution of microstructural attributes such as morphology or orientation of an individual grain within a specific grain neighborhood during mechanical or thermal exposure. Interrupted coupon scale testing, with a separation of testing and microstructural observation is not sufficient due to the small size of the objects to be observed. Thus, the structure evolution of selected grains has to be followed in-situ.

Study on Process of SPHC Steel Solidification

2013 ◽  
Vol 750-752 ◽  
pp. 385-388
Author(s):  
Xue Gang Ma ◽  
Yuan Liang Li ◽  
Rong Li Sang ◽  
Yi Shen
Keyword(s):  
Laser Scanning ◽  
Dendritic Structure ◽  
Solidification Process ◽  
Laser Scanning Microscopy ◽  
Solidification Structure ◽  
Confocal Laser ◽  
In Situ Observation ◽  
Structure Changes ◽  
Sphc Steel

Confocal Laser Scanning Microscopy in situ observation of the solidification process of SPHC Steel and SPHC steel solidification structure changes. The results showed that: SPHC steel in the molten state, the surface of the melt flow of black substance; and with the temperature decreasing, SPHC gradually solidified dendrites continue to grow, increasing new nuclear the dendritic structure continue to refine, to δ-Fe and γ-Fe crystalline phase from the melt.

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