Stress-Dependent Sliding-Induced Nanoscale Wear of Diamond-Like Carbon Studied Using in Situ TEM Nanoindentation

2021 ◽  
Author(s):  
Jhih-Hao Liang ◽  
Zac Milne ◽  
Mehdi Rouhani ◽  
Yi-Pan Lin ◽  
Rodrigo A. Bernal ◽  
...  
Keyword(s):  
Diamond Like Carbon ◽  
Nanoscale Wear ◽  
Stress Dependent

In situ surface oxide reduction with pulsed arc discharge for maximum adhesion of diamond-like carbon coatings

2008 ◽  
Vol 17 (12) ◽  
pp. 2071-2074 ◽  
Author(s):  
Veli-Matti Tiainen ◽  
Antti Soininen ◽  
Esa Alakoski ◽  
Yrjö T. Konttinen
Keyword(s):  
Arc Discharge ◽  
Surface Oxide ◽  
Diamond Like Carbon ◽  
Oxide Reduction ◽  
Carbon Coatings ◽  
Pulsed Arc Discharge ◽  
Pulsed Arc

Tensile Stress-Strain Properties of a-C:H (Diamond-Like Carbon) thin Films

1991 ◽  
Vol 239 ◽  
Author(s):  
Paul D. Garrett ◽  
Brian K. Daniels
Keyword(s):  
Thin Film ◽  
Tensile Stress ◽  
Rf Plasma ◽  
Diamond Like Carbon ◽  
Stress Strain ◽  
Film Coatings ◽  
Strain Behavior ◽  
Thin Film Coatings ◽  
Mode Of Failure

ABSTRACTFundamental mechanical properties of a-C:H (amorphous or “diamond-like” carbon, DLC) thin film coatings have been investigated. Coatings were deposited by a methane-argon RF plasma on polycarbonate films. Tensile stress-strain behavior of the coated polymer was studied using an extensometer to monitor strain. The differences in moduli between uncoated and coated samples were used to calculate apparent coating moduli, which varied from 1 GPA to 82 GPa. The mode of failure was observed via in-situ optical microscopy during deformation. Intrinsic bond strength of the coating/substrate interface was estimated from crack spacings in the deformed coating.

Stress-Dependent In Situ Gas Permeability in the Eagle Ford Shale

2018 ◽  
Vol 123 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Athma R. Bhandari ◽  
Peter B. Flemings ◽  
Ronny Hofmann ◽  
Peter J. Polito
Keyword(s):  
Gas Permeability ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Stress Dependent

The Nanomechanics of Tetrahedral Amorphous Diamond-Like Carbon (ta-C) MEMS

2003 ◽  
Author(s):  
I. Chasiotis ◽  
S. W. Cho ◽  
T. A. Friedmann ◽  
J. P. Sullivan
Keyword(s):  
Strain Analysis ◽  
Film Surface ◽  
Image Correlation ◽  
Diamond Like Carbon ◽  
Tensile Stresses ◽  
Notched Specimens ◽  
Failure Properties ◽  
First Time ◽  
Very High

The mechanics of hydrogen-free tetrahedral amorphous diamond-like carbon (ta-C) MEMS structures have been investigated in connection with their elastic and failure properties. For this purpose, micro-tension specimens of thicknesses between 1.2 μm and 1.8 μm and gage widths of 10 μm or 50 μm have been fabricated by the Sandia National Laboratories (SNL). The mechanical characterization has been conducted via in situ AFM measurements and Digital Image Correlation (DIC) data strain analysis and the deformation fields of uniform tension specimens and internally notched specimens with acute notches (K=27) have been experimentally obtained. The elastic modulus and Poisson’s ratio were measured for the first time directly from the specimens averaging 750 GPa and ν=0.16 respectively, while the tensile strength was found to be very consistent averaging 7.0 GPa. Stressed material domains with smaller dimensions in the vicinity of micronotches exhibited even higher failure strength reaching an average of 11.5 GPa with about 10% scatter. AFM images of specimens under high tensile stresses have also indicated the possibility of an sp3 to sp2 phase transformation on the film surface at very high tensile stresses (>6 GPa).

scholarly journals The Role of In Situ Stress in Organizing Flow Pathways in Natural Fracture Networks at the Percolation Threshold

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Chuanyin Jiang ◽  
Xiaoguang Wang ◽  
Zhixue Sun ◽  
Qinghua Lei
Keyword(s):  
Fluid Flow ◽  
Percolation Threshold ◽  
Fractured Reservoirs ◽  
Fracture Network ◽  
In Situ Stress ◽  
Natural Fracture ◽  
Fracture Aperture ◽  
Dilation Effect ◽  
Stress Dependent

We investigated the effect of in situ stresses on fluid flow in a natural fracture network. The fracture network model is based on an actual critically connected (i.e., close to the percolation threshold) fracture pattern mapped from a field outcrop. We derive stress-dependent fracture aperture fields using a hybrid finite-discrete element method. We analyze the changes of aperture distribution and fluid flow field with variations of in situ stress orientation and magnitude. Our simulations show that an isotropic stress loading tends to reduce fracture apertures and suppress fluid flow, resulting in a decrease of equivalent permeability of the fractured rock. Anisotropic stresses may cause a significant amount of sliding of fracture walls accompanied with shear-induced dilation along some preferentially oriented fractures, resulting in enhanced flow heterogeneity and channelization. When the differential stress is further elevated, fracture propagation becomes prevailing and creates some new flow paths via linking preexisting natural fractures, which attempts to increase the bulk permeability but attenuates the flow channelization. Comparing to the shear-induced dilation effect, it appears that the propagation of new cracks leads to a more prominent permeability enhancement for the natural fracture system. The results have particularly important implications for predicting the hydraulic responses of fractured rocks to in situ stress fields and may provide useful guidance for the strategy design of geofluid production from naturally fractured reservoirs.

scholarly journals Micrometric Growth Defects of DLC Thin Films

2019 ◽  
Vol 5 (4) ◽  
pp. 73 ◽  
Author(s):  
Thibault Maerten ◽  
Cédric Jaoul ◽  
Roland Oltra ◽  
Patrice Duport ◽  
Christophe Le Niniven ◽  
...  
Keyword(s):  
Thin Films ◽  
Defect Density ◽  
Electrochemical Techniques ◽  
Electrochemical Activation ◽  
Diamond Like Carbon ◽  
Growth Defects ◽  
Chemical Inertness ◽  
Highly Sensitive ◽  
Deposition Processes

Defects in diamond-like carbon coatings deposited on corrosion sensitive 100Cr6 steel have been studied. Diamond-like carbon (DLC) thin films are promising for corrosion protection due to chemical inertness and low electrical conductivity. Nevertheless, the performance of these coating is highly sensitive to the presence of uncoated areas. These defects represent the primary way of substrate degradation in aggressive environments. An in situ optical microscopy coupled to an electrochemical activation was developed to reveal micrometric growth defects and observe that they were at the origin of corrosion. A square wave voltammetry was applied to increase the sensitivity of electrochemical techniques based on the detection of the dissolution of the bare metal surface triggered by the presence of uncoated spots. This method can be utilized to quantify defect density arising from vapor deposition processes.

Ex situ and in situ nanoscale wear mechanisms characterization of Zr/Zr x N tribological coatings

Wear ◽  
2018 ◽  
Vol 404-405 ◽  
pp. 82-91 ◽  
Author(s):  
L. Major ◽  
R. Major ◽  
M. Kot ◽  
J.M. Lackner ◽  
B. Major
Keyword(s):  
Wear Mechanisms ◽  
Ex Situ ◽  
Tribological Coatings ◽  
Nanoscale Wear

scholarly journals In situ quantification of diverse titanium dioxide nanoparticles unveils selective endoplasmic reticulum stress-dependent toxicity

2017 ◽  
Vol 11 (1) ◽  
pp. 134-145 ◽  
Author(s):  
Marina Simon ◽  
Gladys Saez ◽  
Giovanna Muggiolu ◽  
Magali Lavenas ◽  
Quentin Le Trequesser ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Titanium Dioxide ◽  
Endoplasmic Reticulum Stress ◽  
Titanium Dioxide Nanoparticles ◽  
Stress Dependent
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