Mechanical Properties of Pure Carbon and Carbonnitrogen Coatings on Thin Film Head Sliders

1996 ◽  
Vol 436 ◽  
Author(s):  
G. Wang ◽  
A. Strojny ◽  
J. M. Sivertsen ◽  
J. H. Judy ◽  
W. W. Gerberich
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Elastic Modulus ◽  
Carbon Films ◽  
Wear Protection ◽  
Pure Carbon ◽  
Wear Damage ◽  
Afm Micrographs ◽  
Better Than ◽  
Made In

AbstractThe mechanical properties of pure carbon (C) and carbon-nitrogen (C:N) coatings on thin film head sliders were investigated by continuous drag testing (CDT) and nano-indentation. Comparisons were made in terms of wear protection, elastic modulus and hardness of these two types of carbon films. The C and C:N thin films with various thickness were deposited on thin film head sliders using a facing target sputtering (FTS) system. After 23,000 revolutions of CDT tests, all the testing head sliders which were uncoated and coated with 90 Å C or C:N exhibited some degree of wear damage as indicated in AFM micrographs where that of the uncoated head was the most severe and that of the C:N coated head was the least. Head sliders coated with 1000Å C and C:N were studied under the TriboscopeTM nano-indenter, where load-displacement curves at different maximum loads were recorded. Elastic modulus and hardness were determined from those curves. The results show that elastic modulus and hardness of C:N are greater than that of C. Therefore, one may conclude that both C and C:N behave like a protective coating for the head slider where C:N is better than C, which could be well related to the larger elastic modulus and hardness of C:N.

Test Methods for Mechanical Properties of Structural Adhesives

2010 ◽  
Vol 97-101 ◽  
pp. 814-817 ◽  
Author(s):  
Jun Deng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Elastic Modulus ◽  
Butt Joint ◽  
Test Methods ◽  
Joint Specimen ◽  
Lap Shear ◽  
Better Than

One of the greatest drawbacks to predicting the behaviour of bonded joints has been the lack of reliable data on the mechanical properties of adhesives. In this study, methods for determining mechanical properties of structural adhesive were discussed. The Young’s modulus, Poisson’s ratio and tensile strength of the adhesive were tested by dogbone specimens (bulk form) and butt joint specimens (in situ form). The shear modulus and shear strength were test by V-notched specimens (bulk form) and thick adherend lap-shear (TALS) joint specimens (in situ form). The test results show that the elastic modulus provided by the manufacturer is too low, the dogbone specimen is better than the butt joint specimen to test the tensile strength and elastic modulus and the TALS joint specimen is better than the V-notched specimen to test the shear strength.

scholarly journals Response of Recycled Brick Aggregate Concrete to High Temperatures

2019 ◽  
Vol 8 (10) ◽  
pp. 224-227
Keyword(s):  
Mechanical Properties ◽  
Air Pollution ◽  
Compressive Strength ◽  
Construction Industry ◽  
Fire Performance ◽  
Demolition Waste ◽  
Aggregate Concrete ◽  
Different Temperatures ◽  
Better Than ◽  
Made In

The abundant availability of demolition waste from construction industry is leading towards a significant problem of disposal, land and air pollution. The natural aggregate resources are also depleting due to development of construction activities. An attempt is made in this study to convert this waste into wealth by substituting the recycled brick from demolition waste to granite aggregate in production of the concrete. The granite aggregate (GA) is replaced with recycled brick aggregate (RBA) by 25% of its weight to produce M15 and M20 grades of concrete. The granite aggregate concrete (GAC) and recycled brick aggregate concrete (RBAC) were subjected to different temperatures between 100 to 1000oC for a duration of 3 hours and the mechanical properties such as compressive strength and flexural strength were examined to assess its fire performance. The response of RBAC is better than GAC at each temperature. The study revealed that the residual strength increases with the increase in grade of concrete at all temperatures.

Influence of Variable Temperature Curing on Mechanical Properties of Fly Ash Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 178-181
Author(s):  
Ya Ding Zhao ◽  
Xue Ying Li ◽  
Ling Chao Kong ◽  
Wei Du
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Variable Temperature ◽  
Improve Performance ◽  
Curing Conditions ◽  
Fly Ash Concrete ◽  
Better Than

Under variable temperature curing conditions(30 oC ~70 oC), concrete with fly ash whose compressive strength, flexural strength, and dynamic elastic modulus are better than ones without fly ash.Compared with constant temperature 20oC, 50 oC and 70 oC, variable temperature curing(VTC) is benefit for the improvement of mechanical properties of 30% fly ash concrete, but which is no advantage to improve performance of 50% fly ash concrete.

The Mechanical Properties of PSA Fibers after Corrosion

2010 ◽  
Vol 146-147 ◽  
pp. 221-224
Author(s):  
Xin Yan Yuan ◽  
Heng Gen Shen ◽  
Zhen Hua Wang ◽  
Wei Li Hou
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Breaking Strength ◽  
Retention Rate ◽  
Acid Corrosion ◽  
Strong Acid ◽  
Elongation Rate ◽  
Scanning Electron ◽  
Better Than ◽  
Made In

In order to reveal the influence of acidic gas SO2 and CaO etc alkali substances which are contained in industrial furnaces smoke to the strength of PSA fiber, tests are made in different acid and alkali conditions, and the changes of its surface morphology were observed by scanning electron microscope (SEM). The results show that: PSA has better acid corrosion resistance than alkali corrosion resistance. Its acid corrosion resistance is similar to the domestic aramid. PSA is better than Nomex in the concentration of 5% H2SO4. Its alkali corrosion resistance is worse than domestic aramid. The retention rate of breaking strength drop to 60.80% and 69.52% respectively after treated in the concentration of 5% H2SO4 for 48 hours and in the concentration of 5% NaOH for 4 hours. The elongation rate decline to 68.14% and 40.22% respectively, and the elongation rate fell to 68.14% and 40.22% respectively. Therefore, the PSA must be dealt against corrosion when used in strong acid or alkali environment.

scholarly journals A Direct Comparison of Three Buckling-Based Methods to Measure the Elastic Modulus of Nanobiocomposite Thin Films

2020 ◽  
Author(s):  
Taylor C. Stimpson ◽  
Daniel A. Osorio ◽  
Emily D. Cranston ◽  
Jose Moran-Mirabal
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Elastic Modulus ◽  
Elastic Moduli ◽  
Input Parameter ◽  
Layer By Layer ◽  
Free Standing ◽  
Film Composition ◽  
Parameter Values

<p>To engineer tunable thin film materials, accurate measurement of their mechanical properties is crucial. However, characterizing the elastic modulus with current methods is particularly challenging for sub-micrometer thick films and hygroscopic materials because they are highly sensitive to environmental conditions and most methods require free-standing films which are difficult to prepare. In this work, we directly compared three buckling-based methods to determine the elastic moduli of supported thin films: 1) biaxial thermal shrinking, 2) uniaxial thermal shrinking, and 3) the mechanically compressed, strain-induced elastic buckling instability for mechanical measurements (SIEBIMM) method. Nanobiocomposite model films composed of cellulose nanocrystals (CNCs) and polyethyleneimine (PEI) were assembled using layer-by-layer deposition to control composition and thickness. The three buckling-based methods yielded the same trends and comparable values for the elastic moduli of each CNC-PEI film composition (ranging from 15 – 44 GPa, depending on film composition). This suggests that the methods are similarly effective for the quantification of thin film mechanical properties. Increasing the CNC content in the films statistically increased the modulus, however, increasing the PEI content did not lead to significant changes. The standard deviation of elastic moduli determined from SIEBIMM was 2-4 times larger than for thermal shrinking, likely due to extensive cracking and partial film delamination. In light of these results, biaxial thermal shrinking is recommended as the method of choice because it affords the simplest implementation and analysis and is the least sensitive to small deviations in the input parameter values, such as film thickness or substrate modulus.</p>

The Structure of Ion-Deposited Crystalline Carbon Films

1976 ◽  
Vol 34 ◽  
pp. 646-647 ◽  
Author(s):  
D. C. Joy ◽  
E. G. Spencer ◽  
P. H. Schmidt ◽  
F. J. Sansalone
Keyword(s):  
Film Thickness ◽  
Carbon Films ◽  
Substrate Material ◽  
Ion Source ◽  
Index Of Refraction ◽  
Cubic Symmetry ◽  
Carrier Gas ◽  
Pure Carbon ◽  
Ion Backscattering ◽  
Made In

Polycrystalline carbon films deposited by an ion source were first studied by Aisenberg and Chabot. Because of the problems they encountered in characterizing these films we have examined similar films made in an apparatus of the type shown in Fig. 1. Samples were deposited on to substrates of NaCl, KC1 or silicon in thicknesses up to 2 μm. Prior to examination in the TEM, the films were dissolved from their substrate material and mounted on grids. The films were highly insulating (∼lO12 ohm cm), optically clear and totally resistant to attack by all common solvents. From ellipsometric measurements the index of refraction was found to be ∼2. Ion backscattering and Auger studies showed the samples to be pure carbon except for the presence of a few percent of the carrier gas (argon, krypton, etc.).Figure 2 shows a micrograph typical of such a film. Crystallites varying in size up to a maximum of a few microns are found randomly distributed over the sample. In general the morphology of the crystals is typical of a cubic symmetry, with a predominance of 90° edges. As the film thickness increases there is a tendency for existing crystals to act as substrates for new crystals.

An Experimental Investigation on the Tensile Behavior of Silane-Modified MMT/Epoxy Nanocomposites

2007 ◽  
Vol 353-358 ◽  
pp. 599-602
Author(s):  
Sung Rok Ha ◽  
Kyong Yop Rhee ◽  
H.H. Shin
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Tensile Behavior ◽  
Reinforcing Effect ◽  
Epoxy Nanocomposite ◽  
Trifunctional Silane ◽  
Dispersion Of Nanoparticles ◽  
Better Than

It is well-known that the mechanical properties of nanocomposites are better than those of conventional composites. One of problems in fabricating nanocomposites is a dispersion of nanoparticles in the composites. In this study, the effect of MMT content on the tensile characteristics of trifunctional silane-treated MMT/epoxy nanocomposite was investigated. It was found that the tensile strength and the elastic modulus increased by over 24% and 83%, respectively, as the content of MMT increases from 2wt% to 10wt%. The improvement of tensile strength and modulus with increasing content of MMT occurs because the reinforcing effect of MMT becomes greater than the deteriorating effect due to the interfacial debonding between MMT and epoxy as the MMT content increases.

Nondestructive Evaluation of Thin Film Microstructures by Picosecond Ultrasonics

1988 ◽  
Vol 142 ◽  
Author(s):  
Humphrey J. Maris ◽  
Holger T. Grahn ◽  
Jan Tauc
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Nondestructive Evaluation ◽  
Time Domain ◽  
Elastic Stress ◽  
Time Dependent ◽  
Ultrasonic Evaluation ◽  
Ultrasonic Measurements ◽  
Made In

AbstractWe describe a technique by which ultrasonic measurements can be made in the picosecond time domain. A light pulse (duration of the order of 0.1 psec) is absorbed at a surface, thereby setting up an elastic stress. This stress launches an elastic pulse into the interior. The propagation of this strain, including its reflection at interfaces within a microstructure, is monitored through measurements of the time-dependent changes of the optical reflectivity. These measurements are made using a time-delayed probe pulse. In these experiments the spatial length of the elastic pulses can be as short as 50 Å. We can therefore use this technique to perform a nondestructive ultrasonic evaluation of thin-film microstructures. We describe here results we have obtained which demonstrate the application of the method to the study of the mechanical properties of thin films, the geometry of microstructures, and the quality of bonding at interfaces.

A Technique for Deducing In-Plane Modulus and Coefficient of Thermal Expansion of a Supported Thin Film

2002 ◽  
Vol 124 (2) ◽  
pp. 274-277 ◽  
Author(s):  
Martin Y. M. Chiang ◽  
Chwan K. Chiang ◽  
Wen-li Wu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Thermal Expansion ◽  
Thermal Stress ◽  
Elastic Modulus ◽  
Coefficient Of Thermal Expansion ◽  
Thermal And Mechanical Properties ◽  
Reduction Scheme ◽  
Coupled Equations

A technique for determining the in-plane modulus and the coefficient of thermal expansion (CTE) of supported thin films has been developed. The modulus and CTE are calculated by solving two coupled equations that relate the curvature of film samples deposited on two different substrates to the thermal and mechanical properties of the constituents. In contrast with the conventional method used to calculate modulus and CTE, which involves differentiation of the thermal stress in the film, this new technique does not require the differentiation of the thermal stress, and can also provide the temperature-dependence of the in-plane CTE and elastic modulus of supported thin films. The data reduction scheme used for deducing CTE and elastic modulus is direct and reliable.

Modeling Nanoscale Rheological and Mechanical Properties of Thin Film Asphalt Binder

2016 ◽  
Author(s):  
Hasan M. Faisal ◽  
Zafrul Hakim Khan ◽  
Rafiqul Tarefder
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Elastic Modulus ◽  
Test Data ◽  
Asphalt Concrete ◽  
Asphalt Binder ◽  
Nanoindentation Test ◽  
Film Material ◽  
Macro Scale ◽  
Sdr Model

Traditionally, mechanical properties of asphalt concrete (AC) is evaluated through macro-scale testing. However, when aggregates are mixed with asphalt binder, it creates a thin film of 20μm to 40μm around the aggregate particles and the primary strength of AC is derived from the interaction between the binder and aggregates. Therefore, to understand the behavior of asphalt concrete it is necessary to study the binder properties in a nanoscale. Nanoindentation test has been adopted to examine the thin film material property. In a nanoindentation test, a loaded nanoindenter is used to indent the sample surface and measure the indenter displacement as a function of load. To this day, most researchers have used the Oliver-Pharr method to analyze the indentation test data and obtain Elastic modulus (E) and hardness (H) of the material. Generally, in a nanoindentation test, there is a loading and unloading phase. In an elasto-plastic material, loading phase has elastic and plastic response and unloading phase has only elastic response. In Oliver-Pharr method, elastic modulus is obtained through the slope of the unloading curve. Therefore, Oliver-Pharr method mostly applicable for the elasto-plastic metals because it does not incorporate any viscous effect. However, in case of visco-elastic material like asphalt, during the unloading phase, the slope of the unloading curve becomes negative due to the viscous flow. Therefore, using Oliver-Pharr (OP) method in this circumstances will yield an inaccurate value of modulus of elasticity. In the current study, the test data was modeled and analyzed using a well-established spring-dashpot-rigid (SDR) model for viscoelastic material to determine the elastic, plastic and viscous properties. The model assumes the indenter displacement is a function of a quadratic spring, a quadratic dashpot and a plastic rigid body. The loading phase of the nanoindentation test has three contributing parameters: elasticity (E), indentation viscosity (η) and hardness (H). During creep, only contributing parameter is indentation viscosity (η) and while unloading the contributing factors are found to be E and η. Nonlinear least square curve fitting technique was employed to model the nanoindentation test data to the SDR model to find out the contributing parameters E, η and H. In addition, the extended dwell time on the asphalt binder samples produced positive load displacement curves, which were further analyzed with Oliver-Pharr method. Comparison between two models results show traditional Oliver-Pharr model predicts the material properties 5 to 10 times lower than SDR model, as Oliver-Pharr does not consider the viscous behavior in the material.

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