scholarly journals Nanoindentation and Nanoscratching of Hard Carbon Coatings for Magnetic Disks

1995 ◽  
Vol 383 ◽  
Author(s):  
T. Y. Tsui ◽  
G. M. Pharr ◽  
W. C. Oliver ◽  
C. S. Bhatia ◽  
R. L. White ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Carbon Film ◽  
Scratch Resistance ◽  
Carbon Films ◽  
Magnetic Disks ◽  
Wear Resistant Coatings ◽  
Beneficial Effects ◽  
Ar Gas ◽  
Scratch Tests ◽  
Cathodic Arc

ABSTRACTNanoindentation and nanoscratching experiments have been performed to assess the mechanical properties of several carbon thin films with potential application as wear resistant coatings for magnetic disks. These include three hydrogenated-carbon films prepared by sputter deposition in a H2/Ar gas mixture (hydrogen contents of 20, 34, and 40 atomic %) and a pure carbon film prepared by cathodic-arc plasma techniques. Each film was deposited on a silicon substrate to thickness of about 300 nm. The hardness and elastic modulus were measured using nanoindentation methods, and ultra-low load scratch tests were used to assess the scratch resistance of the films and measure friction coefficients. The results show that the hardness, elastic modulus, and scratch resistance of the 20% and 34% hydrogenated films are significantly greater than the 40% film, thereby showing that there is a limit to the amount of hydrogen producing beneficial effects. The cathodic-arc film, with a hardness of greater than 59 GPa, is considerably harder than any of the hydrogenated films and has a superior scratch resistance.

Micro-Indentation and Micro-Scratch Tests on Sub-Micron Carbon Films

1988 ◽  
Vol 130 ◽  
Author(s):  
T. W. Wu ◽  
R. A. Burn ◽  
M. M. Chen ◽  
P. S. Alexopoulos
Keyword(s):  
Carbon Film ◽  
Carbon Films ◽  
Silicon Substrates ◽  
Argon Sputtering ◽  
Scratch Tests ◽  
Sputtering Pressure ◽  
Micro Indentation ◽  
Poor Adhesion ◽  
Mtorr Argon ◽  
Hardness Depth

AbstractMicro-indentation and micro-scratch techniques were used to characterize the hardness and the adhesion strength of 0.11 μm thick sputtered carbon f-ilms on Silicon substrates. Hardness depth profiles and critical loads were measured using a microindenter under indentation and scratch testing modes, respectively. The carbon film with 6 mtorr argon sputtering pressure shows better practical adhesion (or higher critical load) and slightly higher hardness. The indentation fracture phenomenon observed on the 30 mtorr film is closely related to its poor adhesion. The failure mechanism will also be discussed.

Comparison of Energetic Carbon Deposition Processes for Use As Ultra-Thin Disk Overcoats

2001 ◽  
Author(s):  
Richard L. White ◽  
Bing K. Yen ◽  
Jan-Ulrich Thiele ◽  
Hans-Herman Schneider ◽  
James H. Rogers ◽  
...  
Keyword(s):  
Carbon Deposition ◽  
Ion Beam ◽  
Scratch Resistance ◽  
Carbon Films ◽  
Maximum Hardness ◽  
Scratch Testing ◽  
Deposition Processes ◽  
Cathodic Arc ◽  
Nitrogen Additions ◽  
Deposition Conditions

Abstract Three different processes, Plasma Enhanced CVD (PECVD), Ion Beam (IB), and Cathodic Arc (CA) have been used to deposit highly energetic carbon films in the 2–10 nm thickness range in commercial, high throughput disk manufacturing tools. The deposition conditions used are typical of those required for disk manufacturing. Raman spectroscopy, I-V measurements, nanoindentation, and AFM based scratch testing have been used to characterize the structural, electrical, and mechanical properties of the films. The measured maximum hardness for the PECVD and IBD films are 28 and 25 GPa, respectively, and found to be influenced by the hardness of the softer substrates for the 70–120nm films available for measurement. The scratch resistance of the CAC films is ∼2× the scratch resistance of the IBD films and 25% greater than the PECVD films. Addition of nitrogen to the films produced by both the PECVD and IB techniques reduces the hardness of the films. Both the Raman and I-V data suggest increasing concentrations of sp2 bonding result from these nitrogen additions.

scholarly journals Nanoindentation and Nanoscratching of Hard Coating Materials for Magnetic Disks

1994 ◽  
Vol 356 ◽  
Author(s):  
T. Y. Tsui ◽  
G. M. Pharr ◽  
W. C. Oliver ◽  
Y. W. Chung ◽  
E. C. Cutiongco ◽  
...  
Keyword(s):  
Tribological Behavior ◽  
Scratch Resistance ◽  
Tribological Performance ◽  
Coating Materials ◽  
Magnetic Disks ◽  
Magnetic Disk ◽  
Wear Resistant Coatings ◽  
Disk Storage ◽  
Boron Suboxide ◽  
Low Load

AbstractNanoindentation and nanoscratching experiments have been performed to assess the mechanical and tribological behavior of three thin film materials with potential application as wear resistant coatings for magnetic disk storage: (1) hydrogenated-carbon (CHx); (2) nitrogenated-carbon (CNx); and (3) boron suboxide (BOx). The hardness and elastic modulus were measured using nanoindentation. Ultra-low load nanoscratching tests were performed to assess the relative scratch resistance of the films and measure their friction coefficients. The mechanical and tribological performance of the three materials are discussed and compared.

scholarly journals Infrared spectroscopy, nano-mechanical properties, and scratch resistance of esthetic orthodontic coated archwires

2014 ◽  
Vol 85 (5) ◽  
pp. 777-783 ◽  
Author(s):  
Dayanne Lopes da Silva ◽  
Emanuel Santos ◽  
Sérgio de Souza Camargo ◽  
Antônio Carlos de Oliveira Ruellas
Keyword(s):  
Mechanical Properties ◽  
Infrared Spectroscopy ◽  
Elastic Modulus ◽  
Scratch Test ◽  
Scratch Resistance ◽  
Load Removal ◽  
Indentation Tests ◽  
Orthodontic Archwires ◽  
Scratch Tests ◽  
Coating Hardness

ABSTRACT Objective:  To evaluate the material composition, mechanical properties (hardness and elastic modulus), and scratch resistance of the coating of four commercialized esthetic orthodontic archwires. Materials and Methods:  The coating composition of esthetic archwires was assessed by Fourier-transform infrared spectroscopy (FTIR). Coating hardness and elastic modulus were analyzed with instrumented nano-indentation tests. Scratch resistance of coatings was evaluated by scratch test. Coating micromorphologic characteristics after scratch tests were observed in a scanning electron microscope. Statistical differences were investigated using analysis of variance and Tukey post hoc test. Results:  The FTIR results indicate that all analyzed coatings were markedly characterized by the benzene peak at about 1500 cm−1. The coating hardness and elastic modulus average values ranged from 0.17 to 0.23 GPa and from 5.0 to 7.6 GPa, respectively. Scratch test showed a high coating elasticity after load removal with elastic recoveries >60%, but different failure features could be observed along the scratches. Conclusion:  The coatings of esthetic archwires evaluated are probably a composite of polyester and polytetrafluoroethylene. Delamination, crack propagation, and debris generation could be observed along the coating scratches and could influence its durability in the oral environment.

Multilayer structure, stress reduction and annealing of carbon film.

2003 ◽  
Vol 791 ◽  
Author(s):  
Peter C.T. Ha ◽  
D. R. McKenzie ◽  
D. Doyle ◽  
D. G. McCulloch ◽  
Richard Wuhrer
Keyword(s):  
Compressive Stress ◽  
Stress Reduction ◽  
Carbon Film ◽  
High Stress ◽  
Carbon Films ◽  
Stress Maximum ◽  
Annealing Step ◽  
Microstructural Effects ◽  
Dc Bias ◽  
Cathodic Arc

ABSTRACTCarbon films deposited by filtered cathodic arc show a high compressive stress which limits their thickness because of delamination. We study three methods of relieving the stress in these films. We first determine the dependence of the stress on DC bias up to bias voltages of 1200V and show that the formula of Davis provides a good fit to the data including the stress maximum in the region of 150–200V and the progressive decrease in stress at higher voltages. In the second method, plasma immersion ion implantation (PIII) was used to create multilayer of alternating high density, high stress (PIII on) films and lower density, low stress (PIII off) films. This method enabled thicker structures to be produced. In the third method we made multilayers using amorphous silicon and carbon layers. Annealing of these layers showed that the stress could be reduced to very low values because of the ability of the silicon layers to absorb compressive stress by contracting after the annealing step. The microstructural effects of PIII were studied by transmission and scanning electron microscopy.

Resonant Tunnelling Behaviour in Multilayered Cold Cathodes Made of Nanoseeded Diamond and Nanocluster Carbon

2001 ◽  
Vol 676 ◽  
Author(s):  
B.S. Satyanarayana ◽  
A. Hiraki
Keyword(s):  
Negative Differential Resistance ◽  
Resonant Tunneling ◽  
Room Temperature ◽  
Carbon Film ◽  
Differential Resistance ◽  
Carbon Films ◽  
Nanocrystalline Diamond ◽  
Resonant Tunnelling ◽  
Cold Cathodes ◽  
Cathodic Arc

ABSTRACTMultilayered cold cathodes made of spin coated nanocrystalline diamond and cathodic arc process grown nanocluster carbon films, were studied. The nanocrystalline diamond was first coated on to the substrate. The nanocluster carbon films were then deposited on the seeded nanocrystalline diamond coated substrates using the cathodic arc process at room temperature. Theresultant hetrostructured microcathodes were observed to exhibit electron emission currents of 1μA/cm2 at fields as low as 1.2 V/μm. Further some of the samples seem to exhibit I-V characteristics witha negative differential resistance region at room temperature conditions. This negative differential resistance or the resonant tunneling behaviour was observed to be dependent on the nanoseeded diamond size and concentration for a given nanocluster carbon film.

Nanoindentation and Scratch Resistance Characteristics of AZ31–WC Nanocomposites

2019 ◽  
Vol 07 (03n04) ◽  
pp. 1950007 ◽  
Author(s):  
Sudip Banerjee ◽  
Suswagata Poria ◽  
Goutam Sutradhar ◽  
Prasanta Sahoo
Keyword(s):  
Elastic Modulus ◽  
Wear Behavior ◽  
Base Alloy ◽  
Stir Casting ◽  
Scratch Resistance ◽  
Wear Volume ◽  
Metal Matrix Nanocomposites ◽  
X Ray ◽  
Weight Percentage ◽  
Scratch Tests

This work examines the effects of WC nanoparticles on nanohardness, elastic modulus and scratch-induced wear behavior of Mg-based metal matrix nanocomposites. Ultrasonic vibrator-equipped stir casting furnace is used to fabricate Mg–WC nanocomposites. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray diffraction (XRD) are employed to conduct the characterizations of base alloy and Mg–WC nanocomposites. Vickers microhardness tester is used to obtain the microhardness values of the fabricated materials. Nanoindentation tests are performed to find the effect of wt.% of WC on the mechanical properties, i.e., nanohardness and elastic modulus. Nanohardness and elastic modulus present nearly 122% and 169.37% increments, respectively, compared to the base alloy when only 2[Formula: see text]wt.% of WC is present as reinforcement. Scratch tests are performed to find the effects of wt.% of WC and applied load on the scratch-induced wear and coefficient of friction (CoF) of the base alloy and Mg–WC nanocomposites. Wear volume also decreases continuously with increase in the weight percentage of WC in magnesium alloy. The COFs of nanocomposites are almost constant but they are inclined to increase with the increase in wt.% of WC. Finally, SEM micrographs of scratch grooves are analyzed to find the wear mechanisms. Abrasive wear mechanism is found to be the dominant one regarding the scratch of Mg–WC nanocomposites.

scholarly journals Hardness, elastic modulus, and structure of very hard carbon films produced by cathodic‐arc deposition with substrate pulse biasing

1996 ◽  
Vol 68 (6) ◽  
pp. 779-781 ◽  
Author(s):  
George M. Pharr ◽  
Daniel L. Callahan ◽  
Shaun D. McAdams ◽  
Ting Y. Tsui ◽  
Simone Anders ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Carbon Films ◽  
Hard Carbon ◽  
Cathodic Arc Deposition ◽  
Cathodic Arc ◽  
Arc Deposition

Benzylamine Tartrate as an Organic Glass Substrate for Carbon Films by Evaporation

1970 ◽  
Vol 28 ◽  
pp. 484-485
Author(s):  
A. C. Faberge
Keyword(s):  
Vapor Pressure ◽  
Viscous Liquid ◽  
Glass Substrate ◽  
Room Temperature ◽  
Carbon Film ◽  
Carbon Films ◽  
Organic Glass ◽  
Spectroscopic Examination ◽  
Polymeric Substrates

Benzylamine tartrate (m.p. 63°C) seems to be a better and more convenient substrate for making carbon films than any of those previously proposed. Using it in the manner described, it is easy consistently to make batches of specimen grids as open as 200 mesh with no broken squares, and without individual handling of the grids. Benzylamine tartrate (hereafter called B.T.) is a viscous liquid when molten, which sets to a glass. Unlike polymeric substrates it does not swell before dissolving; such swelling of the substrate seems to be a principal cause of breakage of carbon film. Mass spectroscopic examination indicates a vapor pressure less than 10−9 Torr at room temperature.

Carbon Film Deposition On Silicon Using Low Energy Ion Beams

1991 ◽  
Vol 223 ◽  
Author(s):  
Qin Fuguang ◽  
Yao Zhenyu ◽  
Ren Zhizhang ◽  
S.-T. Lee ◽  
I. Bello ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Carbon Film ◽  
Carbon Films ◽  
Film Deposition ◽  
Ion Energy ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Post Implantation ◽  
Beam Deposition

ABSTRACTDirect ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.

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