Simulations on Sliding Process between Si-DLC and DLC Films on a Water-Lubricated Condition

2010 ◽  
Vol 29-32 ◽  
pp. 1408-1413 ◽  
Author(s):  
Hui Qing Lan ◽  
Can Liu ◽  
Takahisa Kato

Diamond like carbon (DLC) films have been extensively studied over the past decades due to their unique combination of properties, in particular, silicon-doped DLC (Si-DLC) films are of significant interest for tribological effects, they had a very low friction coefficient and possess the potential to improve wear performance in humid atmospheres and at higher temperature. But many experimental results of the Si-DLC films showed that their tribological properties changed greatly on different silicon contents. In the paper, molecular dynamics (MD) simulations were used to study a sliding friction process between Si-DLC and DLC films on an un-lubricated and a water-lubricated condition respectively. The results have been shown that a transfer film between the Si-DLC and DLC films was formed on the un-lubricated condition. In contrast, a boundary lubrication layer was found on the water-lubricated condition. Moreover, the friction force on the un-lubricated condition was larger than those on the water-lubricated condition.

2011 ◽  
Vol 675-677 ◽  
pp. 953-956
Author(s):  
Yang Wang ◽  
Hui Qing Lan ◽  
Can Liu

Diamond-like carbon films have been extensively studied over the past decades due to their unique combination of properties, in particular, Si-DLC films are of significant interest for tribological effects. They possess the potential to improve wear performance in humid atmospheres and at higher temperatures. MD simulations were carried out to generate Si-DLC films at different silicon contents from 0 to 50%, in order to theoretically investigate the influence of silicon contents on microstructures and tribological properties between Si-DLC films. The results show that the sp3/sp2 ratio in Si-DLC films increases with the increasing silicon content. The MD simulation results suggest that the friction force increases with addition of silicon to DLC films. The bond numbers of interfilms have showed that the silicon addition promotes the bonding of interfilms forming, which results in the friction force increased.


2011 ◽  
Vol 393-395 ◽  
pp. 499-502
Author(s):  
Zhi Ping Wang ◽  
Feng Yuan

The oxidation film was prepared by anode oxidation method on ZL101 aluminium surface, its morphologies, compositions and phases were characterized with SEM (Scanning Electron Microscope), optical profiler, EDS (Energy Disperse Spectroscopy), respectively, its friction coefficient and abrasion performance were analyzed by wear test, and its wear mechanism was discussed. The results show that the thickness of anode oxidation layer is about 35-40m, under dry friction condition, sliding friction coefficient is 0.65-0.72, the wear forms are abrasive attrition and adhesion wear, the low friction pair between furrows effect and adhesion effect improves the wear performance of anode oxidation film on ZL101 aluminum alloy surface.


1999 ◽  
Vol 5 (S2) ◽  
pp. 836-837
Author(s):  
R. Mitra ◽  
W.A. Chiou ◽  
A.Madan ◽  
R. Hoffman ◽  
J.R. Weertman

There has been a significant interest in the development of dispersion-hardened aluminum for many years for high specific strength and modulus. Such materials are usually processed by powder or ingot metallurgy routes. In this study, Al3 Ti dispersion hardened Al was obtained by annealing Al-Ti multilayers. Al-Ti multilayered films have been characterized in the past by observing the structure of the layers, as well as tensile properties and hardness. This paper reports the structure of Al-Ti multilayers and the evolution of matrix and dispersoid microstructure on annealing.The Al-Ti multilayered structures were prepared by magnetron sputtering using Al and Ti as targets and either Si (100) or NaCl as substrates. The bi-layer thickness was maintained around 16 nm with Ti constituting 12% of the total. The substrate was alternately moved below the Al and Ti targets for the purpose of deposition. The as-deposited film on the substrate and NaCl salts were annealed at 400°C for periods between 1 and 24 h in a vacuum (10−5 torr) furnace.


2015 ◽  
Vol 91 ◽  
pp. 151-159 ◽  
Author(s):  
Mamoun Fellah ◽  
Mohammed Abdul Samad ◽  
Mohamed Labaiz ◽  
Omar Assala ◽  
Alain Iost

2021 ◽  
Author(s):  
Priya kaushal ◽  
Tarun Chaudhary ◽  
Gargi Khanna

Abstract The present work is based on the computational study of MoS2 monolayer and effect of tensile strain on its atomic level structure. The bandgap for MoS2 monolayer, defected MoS2 monolayer and Silicon-doped monolayer are 1.82 eV (direct bandgap), 0.04 (indirect bandgap) and 1.25eV (indirect bandgap), respectively. The impact of tensile strain (0-0.7%) on the bandgap and effective mass of charge carriers of these three MoS2 structure has been investigated. The bandgap decrease of 5.76%, 31.86% and 6.03% has been observed in the three structures for biaxial strain while the impact of uniaxial strain is quite low. The impact of higher temperature on the bandgap under biaxial tensile strain has been also analyzed in this paper. These observations are extremely important for 2D material-based research for electronic applications.


Children ◽  
2018 ◽  
Vol 5 (8) ◽  
pp. 111 ◽  
Author(s):  
Anna Esparham ◽  
Sanghamitra Misra ◽  
Erica Sibinga ◽  
Timothy Culbert ◽  
Kathi Kemper ◽  
...  

Pediatric integrative medicine (PIM) is of significant interest to patients, with 12% of the general pediatric population and up to 80% of children with chronic conditions using PIM approaches. The field of PIM has evolved over the past 25 years, approaching child health with a number of guiding principles: preventive, context-centered, relationship-based, personalized, participatory, and ecologically sustainable. This manuscript reviews important time points for the field of PIM and reports on a series of meetings of PIM leaders, aimed at assessing the state of the field and planning for its future. Efforts in the first decade of the 2000s led to increased visibility in academic and professional pediatric organizations and through international listservs, designed to link those interested in and practicing PIM, all of which continue to flourish. The PIM leadership summits in recent years resulted in specific goals to advance PIM further in the following key areas: research, clinical practice, professional education, patient and family education, and advocacy and partnerships. Additionally, goals were developed for greater expansion of PIM professional education, broader support for pediatric PIM research, and an expanded role for PIM approaches in the provision of pediatric care.


Author(s):  
Gulraiz Ahmed ◽  
Nektaria Koursari ◽  
Anna Trybala ◽  
Victor M. Starov

Wetting of deformable substrates has gained significant interest over the past decade due to its extensive applications and uses. This interest has developed due to technological advances which are able to capture interfacial behavior taking place when a liquid droplet is placed on a deformable substrate. Researchers have developed different theories to explain processes taking place in the process of wetting of deformable/soft substrates. For the scope of this review, we will consider the fluid to be Newtonian, partially wetting, and surface forces are incorporated with the help of disjoining/conjoining pressure acting in the vicinity of the apparent, three-phase contact line. The following subjects are briefly reviewed: (i) Equilibrium of droplets on soft substrates. It is shown that properties of the disjoining/conjoining pressure isotherm and properties of the deformable substrate determine both the shape of the liquid droplet and deformation of the substrate; (ii) Equilibrium conditions of droplets on deformable substrates. It is shown that for a droplet to be at equilibrium on a deformable substrate under consideration, Jacobi’s sufficient condition is satisfied; (iii) Hysteresis of contact angle of sessile droplets on deformable substrates. It is shown that as the elasticity of the deformable substrate is increased, both advancing and receding contact angles are reduced.


2020 ◽  
Vol 12 (9) ◽  
pp. 168781402095779
Author(s):  
He Pan ◽  
Yang Zhang

When light alloys used in coal mine, the sparks generated by mechanical friction and impacts are the main effective ignition source. While the hot surfaces are concomitant in friction process, prior to the occurrence of mechanical sparks, whether the hot surfaces will be an effective ignition source. Then this paper focuses on the development of hot surfaces generated by TC4 titanium alloy at the low friction velocities. Experiments and finite element simulation methods were used together to describe the temperature field of TC4 titanium alloy. It was found that the temperature of hot surfaces increased with the load and increased much faster at higher relative speed. By means of regression analysis, the variation law of friction coefficient and contact pressure with loads and the variation law of hot surface temperature with friction coefficient and pressure were studied, then the fitting curve of hot surface temperature was obtained. The results of calculations and experiments indicate that hot surfaces generated by light alloy was possible to be an effective ignition source for methane air mixture in coal mine.


2017 ◽  
Vol 14 (2) ◽  
pp. 67-80 ◽  
Author(s):  
Cun Ji ◽  
Chao Zhao ◽  
Li Pan ◽  
Shijun Liu ◽  
Chenglei Yang ◽  
...  

Time series classification (TSC) has attracted significant interest over the past decade. A shapelet is one fragment of a time series that can represent class characteristics of the time series. A classifier based on shapelets is interpretable, more accurate, and faster. However, the time it takes to find shapelets is enormous. This article will propose a fast shapelet (FS) discovery algorithm based on important data points (IDPs). First, the algorithm will identify IDPs. Next, the subsequence containing one or more IDPs will be selected as a candidate shapelet. Finally, the best shapelets will be selected. Results will show that the proposed algorithm reduces the shapelet discovery time by approximately 14.0% while maintaining the same level of classification accuracy rates.


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