New method for producing double replica for observing and a precipitates

1990 ◽  
Vol 48 (4) ◽  
pp. 842-843
Author(s):  
Krystyna Spiradek ◽  
Aleksandra Czyrska-Filemonowicz ◽  
Erwin M. Hörl
Keyword(s):  
Grain Boundaries ◽  
Surface Structure ◽  
Metallic Matrix ◽  
Ethanol Solution ◽  
New Method ◽  
Horizontal Position ◽  
Great Care ◽  
Metal Plates ◽  
Sandwich Type ◽  
Bottom Side

In metallurgy and metal physics it is very often necessary to analyse the types, shapes, sizes etc. of precipitates in a metal or metal alloy. Furthermore it is often of importance to know the distribution of these particles along the grain boundaries and within the grains. For this analysis a new EM technique has been developed.The procedure of this technicue is the following:First of all specimens are prepared of the materials to be investigated in such a way that one obtains thin metal plates or foils of a thickness of 0,1 to 0,01 mm. This foils are etched in a H2O solution of 10 % H2CrO3 for revealing the surface structure. Afterwards carbon is avaporated on both sides of the foils. In the next step a square grid of 3 mm х 3 mm is scratched into the foil on both sides in such a way that the grid of the top side is exactly positioned over the grid of the bottom side. After this procedure the specimens are inserted into an ethanol solution of 10 % bromine in a horizontal position till the metallic matrix is solved and the precipitates are left. This step takes approx. 24 hours. Afterwards the replicas consisting of the two carbon layers with the precipitates between them are cleaned using firstly ethanol afterwards 50% ethanol in destilled water and finally just destilled water (.5 hours in each bath). In the next step the replicas are put on EM grids of sandwich type. Great care is necessary in this step in order to avoid shifting of the carbon layers and disturbances of the positions of the precipitates. These replicas are now ready for TEM as well as SEM investigations, as soon as they are dry.

Explosive Welding Using Underwater Shock Wave Generated by the Detonation of the Detonating Code

2011 ◽  
Vol 673 ◽  
pp. 265-270 ◽  
Author(s):  
Akihisa Mori ◽  
Li Qun Ruan ◽  
Kazumasa Shiramoto ◽  
Masahiro Fujita
Keyword(s):  
Shock Wave ◽  
Sound Velocity ◽  
Detonation Velocity ◽  
Explosive Welding ◽  
New Method ◽  
Underwater Shock Wave ◽  
Metal Plates ◽  
Experimental Parameters ◽  
Underwater Shock ◽  
Point Velocity

Detonating code is a flexible code with an explosive core. It is used to transmit the ignition of explosives with high detonation velocity in the range of 5.5 to 7 km/s. However, it is difficult to use detonating code for the explosive welding of common metals since the horizontal point velocity usually exceeds the sound velocity. Hence, in the present work, a new method using underwater shock wave generated by the detonation of detonating code was tried. The details of the experimental parameters and the results are presented. From the results it is observed that the above technique is suitable to weld thin metal plates with relatively less explosives.

Structure Determination of the Nisi2(111) Surface Using Medium Energy Ion Scattering with Monolayer Resolution

1990 ◽  
Vol 202 ◽  
Author(s):  
J. Vrijmoeth ◽  
P.M. Zagwijn ◽  
J.W.M. Frenken ◽  
J.F. van der Veen
Keyword(s):  
Surface Structure ◽  
Structure Determination ◽  
New Method ◽  
Medium Energy ◽  
Ion Scattering ◽  
Triple Layer ◽  
Medium Energy Ion Scattering

ABSTRACTThe surface structure of epitaxial NiSi2 films grown on Si (111) has been determined using a new method. The backscattering signals from subsequent Ni layers in the NiSi2 (111) surface are resolved.The topology of the NiSi2 (111) surface is concluded to be bulklike, i.e., it is terminated by a Si – Ni – Si triple layer.

Radical induced intermolecular linkage and energy level modifications of a porphyrin monolayer

2017 ◽  
Vol 53 (6) ◽  
pp. 1104-1107 ◽  
Author(s):  
Abdolreza Jahanbekam ◽  
Colin Harthcock ◽  
David Y. Lee
Keyword(s):  
Energy Level ◽  
Scanning Tunneling Microscopy ◽  
Surface Structure ◽  
Energy Levels ◽  
New Method ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Molecular Scale

A new method to directly modify the surface structure and energy levels of a porphyrin monolayer was examined with molecular-scale resolution using scanning tunneling microscopy and spectroscopy (STM and STS) and presented in this communication.

Gold nanoplating as a new method for the quantification of the electrochemical activity of grain boundaries in polycrystalline metals

2012 ◽  
Vol 24 ◽  
pp. 97-99 ◽  
Author(s):  
R. Gaggiano ◽  
E. Martinez Lombardia ◽  
I. De Graeve ◽  
L. Lapeire ◽  
K. Verbeken ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Electrochemical Activity ◽  
New Method ◽  
Polycrystalline Metals

New Method for Estimation of Grain Boundaries Contribution to Resistance of Highly Doped Polysilicon

1998 ◽  
Vol 37 (Part 1, No. 12B) ◽  
pp. 6974-6976 ◽  
Author(s):  
Serguei Spoutai ◽  
Hui-Gon Chun ◽  
Kang-Ho Ahn
Keyword(s):  
Grain Boundaries ◽  
New Method

Slipping Dynamics of Slender-Beam Payloads During Lay-Down Operations

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Shenghai Wang ◽  
Aldo Ferri ◽  
William Singhose
Keyword(s):  
Friction Coefficient ◽  
Flat Surface ◽  
New Method ◽  
Line Contact ◽  
Horizontal Position ◽  
Vertical Orientation ◽  
Dynamic Analyses ◽  
Theoretical Predictions

When laying down a long slender beam from a near-vertical orientation, to a horizontal position on a flat surface, the payload may slip and move suddenly in unintended and unpredictable ways. This occurs during crane operations when the movements of the overhead trolley and lowering of the hoist cable are not properly coordinated. The payload's unintended sliding can potentially cause damage and injure people. This paper presents static and dynamic analyses of slender-beam payload lay-down operations that establish a structured method to predict the safe conditions for lay-down operations. Also, a new method to measure the friction coefficient of surface-to-line contact is proposed. Lay-down experiments are carried out to verify the theoretical predictions.

Superhydrophobic Nanocrystalline Nickel Films Inspired by Lotus Leaf

2008 ◽  
Vol 1132 ◽  
Author(s):  
Mehdi Shafiei ◽  
Ahmet T. Alpas
Keyword(s):  
Contact Angle ◽  
Grain Size ◽  
Surface Structure ◽  
Water Contact Angle ◽  
Surface Texture ◽  
High Water ◽  
New Method ◽  
Water Contact ◽  
Lotus Leaf ◽  
Tip Radius

ABSTRACTA new method to fabricate superhydrophobic hard films is described. Surface texture of lotus leaf was replicated on an acetate film, on which a nanocrystalline (NC) Ni coating with a grain size of 30 ± 4 nm and a hardness of 4.42 GPa was electrodeposited. The surface texture consisted of conical protuberances with a height of 10.0 ± 2.0 0m and a tip radius of 2.5 ± 0.5 0m. An additional electrodeposition for 120 s and 300 s was used to locally modify the surface structure by depositing ‘Ni crowns' on the protuberances that increased their height to 14.0 ± 2.0 0m and their tip radius to 6.0 ± 0.5 0m. The modified structures were then treated with a perfluoropolyether (PFPE) solution, which provided a high water contact angle of 156°, i.e., comparable to the naturally superhydrophobic lotus leaf. The increased hydrophobicity as a result of surface structure and chemistry modifications was evident compared to a smooth NC Ni sample, which had a contact angle of 64°.

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