Investigation of stress corrosion-enhanced plastic deformation using atomic force microscope

2002 ◽  
Vol 47 (12) ◽  
pp. 1053-1056
Author(s):  
Song Liang ◽  
Lijie Qiao ◽  
Wuyang Chu
Keyword(s):  
Plastic Deformation ◽  
Atomic Force Microscope ◽  
Stress Corrosion ◽  
Atomic Force

The Role of Plastic Deformation in Nanometer-Scale Wear

2010 ◽  
Vol 64 ◽  
pp. 25-32 ◽  
Author(s):  
Philip Egberts ◽  
Roland Bennewitz
Keyword(s):  
Plastic Deformation ◽  
Atomic Force Microscope ◽  
Edge Dislocation ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Nanometer Scale ◽  
Single Asperity ◽  
Atomic Force ◽  
Low Load

Scratches on KBr(100) surfaces were produced and examined with an atomic force microscope (AFM) operated in an ultra-high vacuum (UHV) environment. Scratches with lengths on the order of 100s of nanometers and depths on the order of atomic layers were investigated. Non-contact AFM topographic images of scratches revealed screw and edge dislocation activity around the scratch sites, illuminating the role of plastic deformation in wear processes. Friction coefficients of approximately 0.3 were measured during scratching, more comparable to macroscopic friction experiments than those measured in low-load, single asperity experiments.

An investigation of nanoindentation tests on the single crystal copper thin film via an atomic force microscope and molecular dynamics simulation

2007 ◽  
Vol 221 (2) ◽  
pp. 259-266 ◽  
Author(s):  
D Huo ◽  
Y Liang ◽  
K Cheng
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Size Effect ◽  
Single Crystal ◽  
Atomic Force Microscope ◽  
Md Simulations ◽  
Single Crystal Copper ◽  
Atomic Force

Nanoindentation tests performed in an atomic force microscope have been utilized to directly measure the mechanical properties of single crystal metal thin films fabricated by the vacuum vapour deposition technique. Nanoindentation tests were conducted at various indentation depths to study the effect of indentation depths on the mechanical properties of thin films. The results were interpreted by using the Oliver-Pharr method with which direct observation and measurement of the contact area are not required. The elastic modulus of the single crystal copper film at various indentation depths was determined as 67.0 > 6.9 GPa on average, which is in reasonable agreement with the results reported by others. The indentation hardness constantly increases with decreasing indentation depth, indicating a strong size effect. In addition to the experimental work, a three-dimensional nanoindentation model of molecular dynamics (MD) simulations with embedded atom method (EAM) potential is proposed to elucidate the mechanics and mechanisms of nanoindentation of thin films from the atomistic point of view. MD simulations results show that due to the size effect no distinct dislocations were observed in the plastic deformation processes of the single crystal copper thin films, which is significantly different from the plastic deformation mechanism in bulk materials.

Analysis of the Behavior of a Clad Material Al-Zinag-Al

2007 ◽  
Vol 551-552 ◽  
pp. 337-340 ◽  
Author(s):  
S.R. Casolco ◽  
J. Negrete-Sánchez ◽  
M. López Parra ◽  
Gabriel Torres-Villaseñor
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Atomic Force Microscope ◽  
Tensile Testing ◽  
Superplastic Deformation ◽  
Single Layer ◽  
Aluminum Film ◽  
Atomic Force

In the present work, we studied the nanostructural behavior of a denominated alloy Clad- Zinag, which is composed of a single layer of Zinag coated on both surfaces by an aluminum film. The alloy was then deformed by two different processes, one in which a superplastic conformed technique was applied and the second was by way of tensile testing. For both techniques, the alloy was examined and analyzed by viewing the materials topography with an atomic force microscope (AFM). From these techniques we were able to observe both processes of plastic deformation and the presence of marks which correspond to bands of grain sliding. This mechanism is a result of superplastic deformation, and influences the grain size of aluminum. Nevertheless, we must clarify that the name of mesoscopic band of slides, is based on a study according to Vinogradov.

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

Imaging polymers, proteins and dna in aqueous solutions with the atomic force microscope

1989 ◽  
Vol 47 ◽  
pp. 32-33
Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Sequencing ◽  
Aqueous Solutions ◽  
Atomic Force Microscope ◽  
Piezoelectric Crystal ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Optical Lever

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.

The atomic-force microscope and its future in biology

1993 ◽  
Vol 51 ◽  
pp. 704-705
Author(s):  
Jean-Paul Revel
Keyword(s):  
Silicon Nitride ◽  
Laser Beam ◽  
Atomic Force Microscope ◽  
Scanning Tunneling Microscope ◽  
Point Of View ◽  
Scanning Tunneling ◽  
Close Relative ◽  
Tunneling Microscope ◽  
Atomic Force ◽  
Sharp Point

The last few years have been marked by a series of remarkable developments in microscopy. Perhaps the most amazing of these is the growth of microscopies which use devices where the place of the lens has been taken by probes, which record information about the sample and display it in a spatial from the point of view of the context. From the point of view of the biologist one of the most promising of these microscopies without lenses is the scanned force microscope, aka atomic force microscope.This instrument was invented by Binnig, Quate and Gerber and is a close relative of the scanning tunneling microscope. Today's AFMs consist of a cantilever which bears a sharp point at its end. Often this is a silicon nitride pyramid, but there are many variations, the object of which is to make the tip sharper. A laser beam is directed at the back of the cantilever and is reflected into a split, or quadrant photodiode.

The application of atomic force microscope in microbiological research

2014 ◽  
Vol 5 (1) ◽  
pp. 27-30
Author(s):  
Małgorzata Tokarska-Rodak ◽  
Maria Kozioł-Montewka ◽  
Jolanta Paluch-Oleś ◽  
Dorota Plewik ◽  
Grażyna Olchowik ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Atomic Force ◽  
Microbiological Research
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