Investigating atomic structure of thin carbon film under mechanical stress and frictional heat generation

The burnishing wear of carbon films found in dynamic microdevices could be attributed to both mechanical stress and temperature rise by frictional heat generation. In this study, novel modeling and experiment were performed to investigate the burnishing wear mechanism of carbon film during high speed sliding contact. An improved thermomechanical contact model for a single asperity was extended to rough surface contact. The contact stress and surface temperature rise were examined at various contact conditions. To verify the thermal degradation of the carbon film by frictional heat flux, micro-Raman spectroscopy measurement was performed on actual burnishing failure sample.

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Thermo-Mechanical Contact and Micro-Wear in Head Disk Interface

ASME/STLE 2011 Joint Tribology Conference ◽

10.1115/ijtc2011-61059 ◽

2011 ◽

Cited By ~ 4

Author(s):

Sungae Lee ◽

Chang-Dong Yeo

Keyword(s):

Heat Generation ◽

Carbon Film ◽

Dynamic Contact ◽

Frictional Heat ◽

Sliding Velocity ◽

Head Disk Interface ◽

Mechanical Contact ◽

Disk Interface ◽

Frictional Heat Generation ◽

Contact Parameters

Thermo-mechanical contact and micro-wear of head disk interface (HDI) are investigated using the improved HDI contact model and theories of frictional heat generation and heat transfer. In analytical simulations, dynamic contact parameters such as material properties, sliding velocity, and surface interference are based on actual HDI design and operation. The resulting contact pressure and temperature distribution show that the micro-wear on the carbon film of a head slider would be significantly attributed to the degradation of carbon material caused by frictional heat generation during sliding contact.

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Hydrated form of some clay minerals observed using a film sealed environmental cell

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107502 ◽

1978 ◽

Vol 36 (1) ◽

pp. 72-73

Author(s):

N. Kohyama ◽

K. Fukushima ◽

A. Fukami

Keyword(s):

Clay Minerals ◽

Morphological Changes ◽

Carbon Film ◽

Electron Microscopic Observation ◽

Adsorbed Water ◽

Electron Microscopic ◽

Hydrated Form ◽

Thin Carbon ◽

Environmental Cell ◽

Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

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Alkaline Dissociation Products of Lumbricus Terrestris Hemoglobin Viewed with the STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098678 ◽

1981 ◽

Vol 39 ◽

pp. 434-435

Author(s):

O. H. Kapp ◽

M. Ohtsuki ◽

N. Robin ◽

S. N. Vinogradov ◽

A. V. Crewe

Keyword(s):

Carbon Film ◽

Lumbricus Terrestris ◽

Uranyl Acetate ◽

Acetate Solution ◽

Oxygen Carriers ◽

Complex Molecules ◽

Thin Carbon ◽

Thin Carbon Film ◽

Multiple Copies ◽

Hill Coefficients

Annelid extracellular hemoglobins are among the largest known proteins (M.W = 3.9 x 106), and together with the hemocyanins are the largest known oxygen carriers. They display oxygen affinities generally higher than those o vertebrate hemoglobins with Hill coefficients ranging from slightly higher than unity to values as high as 5-6. These complex molecules are composed of multiple copies of as many as six different polypeptides and posse: approximately 150 hemes per molecule.The samples were diluted to 100-200 μg/ml with distilled water just before application to a thin carbon film (∽15 Å thick). One percent (w/v) uranyl acetate solution was used for negative staining for 2 minutes and dried in air. The specimens were examined with the high resolution STEM. Their general appearance is that of a hexagonal bilayer (Fig. 1), each layer consisting of six spheroidal subunits. The corner to corner hexagonal dimensic is approximately 300 Å and the bilayer thickness approximately 200 Å.

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