GRAPHITE EXPANDED AS A FILM-FORMING MATERIAL ON A STEEL SURFACE

Tribologia ◽  
2017 ◽  
pp. 81-85
Author(s):  
Aleksandra REWOLIŃSKA ◽  
Karolina PERZ ◽  
Grzegorz KINAL
Keyword(s):  
Observational Studies ◽  
Steel Surface ◽  
Film Formation ◽  
Operating Conditions ◽  
Reciprocating Motion ◽  
Forming Process ◽  
Film Forming ◽  
Graphite Film

The results of observational studies of the emerging graphite film on the steel surface are presented. The association – steel pin and graphite element – reciprocating motion was employed. The results show the possible mechanism of graphite film formation for the various stages of association work under various operating conditions. For a water-impregnated graphite element, the film forming process takes place faster than for a dry element.

Film formation in EHL contacts with oil-impregnated sintered materials

2018 ◽  
Vol 70 (4) ◽  
pp. 612-619 ◽  
Author(s):  
Milan Omasta ◽  
Martin Ebner ◽  
Petr Šperka ◽  
Thomas Lohner ◽  
Ivan Krupka ◽  
...  
Keyword(s):  
Film Thickness ◽  
Sintered Material ◽  
Film Formation ◽  
Elastohydrodynamic Lubrication ◽  
Lubricant Film ◽  
Operating Conditions ◽  
Lubricant Film Thickness ◽  
Content Type ◽  
Film Forming ◽  
Highly Loaded

PurposeThe purpose of this study is to investigate lubricant film-forming capability of oil-impregnated sintered material in highly loaded non-conformal contacts. This self-lubrication mechanism is well described in lightly loaded conformal contacts such as journal bearings; however, only a little has been published about the application to highly loaded contacts under elastohydrodynamic lubrication regime (EHL).Design/methodology/approachThin film colorimetric interferometry is used to describe the effect of different operating conditions on lubricant film formation in line contacts.FindingsUnder fully flooded conditions, the effect of porous structure can be mainly traced back to the different elastic properties. When the contact is lubricated only by oil bleeding from the oil-impregnated sintered material, starvation is likely to occur. It is indicated that lubricant film thickness is mainly governed by oil bleeding capacity. The relationship between oil starvation parameters corresponds well with classic starved EHL theory.Practical implicationsTo show practical, relevant limitations of the considered self-lubrication system, time tests were conducted. The findings indicate that EHL contact with oil-impregnated sintered material may provide about 40 per cent of fully flooded film thickness.Originality/valueFor the first time, the paper presents results on the EHL film-forming capability of oil-impregnated sintered material by measuring the lubricant film thickness directly. The present paper identifies the phenomena involved, which is necessary for the understanding of the behavior of this complex tribological system.

New surface treatment techniques to minimize copper alloy leaching in drinking water

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
Norikazu Sugaya
Keyword(s):  
Surface Treatment ◽  
Raw Materials ◽  
Organic Film ◽  
Forming Process ◽  
Mixed Acid ◽  
Treatment Techniques ◽  
Acid Washing ◽  
Washing Process ◽  
Film Forming ◽  
Materials Used

This new surface treatment is simple and easy as well as low in cost. The processes can even be performed by hand. Pharmaceutical raw materials used for the surface treatment, such as hydrochloric acid and nitric acid used in a mixed acid washing process and vegetable oil used in an organic film forming process, are easily obtained in many countries.

scholarly journals Film forming PVA-based cleaning systems for the removal of corrosion products from historical bronzes

2018 ◽  
Vol 90 (3) ◽  
pp. 507-522 ◽  
Author(s):  
Erica I. Parisi ◽  
Nicole Bonelli ◽  
Emiliano Carretti ◽  
Rodorico Giorgi ◽  
Gabriel M. Ingo ◽  
...  
Keyword(s):  
Film Formation ◽  
Poly Vinyl Alcohol ◽  
Complexing Agent ◽  
Film Forming ◽  
Innovative System ◽  
Mechanical Procedure ◽  
Cleaning Procedures ◽  
Film Formation Mechanism

AbstractThis paper presents an innovative poly(vinyl)alcohol-based film forming system, specifically devised for the controllable and selective cleaning of copper-based artifacts. Traditional cleaning procedures are commonly performed using mechanical and/or chemical methods. Unfortunately, both these methods present some limitations related to both the poor selectivity and invasiveness in case of the mechanical procedure, and to the scarce control over the involved reactions when dealing with a chemical approach. The innovative system proposed in this work allows combining the advantages of chemical and mechanical treatments thanks to the confinement of a complexing agent (EDTA) within a fluid, polymeric matrix, that is able to form a solid thin film upon drying. After treatment, the polymeric film can be completely removed from the artwork through a gentle peeling action. In this contribution, the film formation mechanism was investigated by means of thermal analysis and rheology; the role of plasticizers, volatile solvent fraction, and quantity of loaded EDTA is also discussed. Finally, the results of cleaning tests performed on artificially aged samples, and on a real case study, the “Fontana dei Mostri Marini” by Pietro Tacca in Florence, are presented.

scholarly journals Adsorption Behaviour of Film-forming Amine on Pre-oxidized Carbon Steel Surface

2021 ◽  
Author(s):  
Lin Genxian ◽  
Sun Yun ◽  
Liu Canshuai ◽  
Fang Jun ◽  
Song Lijun ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Steel Surface ◽  
Adsorption Behaviour ◽  
Carbon Steel Surface ◽  
Film Forming ◽  
Oxidized Carbon

Development of Mucoadhesive Film-Forming Systems Containing Black Ginger Extract for Aphthous Ulcers

2021 ◽  
Vol 901 ◽  
pp. 104-110
Author(s):  
Nattanich Wattanaphraya ◽  
Somkamol Manchun ◽  
Siriporn Taokaew ◽  
Worawut Kriangkrai
Keyword(s):  
Film Formation ◽  
Aphthous Ulcer ◽  
Alternative Formulation ◽  
Ginger Extract ◽  
Inflammatory Agent ◽  
Mucoadhesive Polymers ◽  
Aphthous Ulcers ◽  
Film Forming ◽  
Gradual Release

Film-forming systems (FFSs) were developed by using Eudragit® E100 as a film former. Kaempferia parviflora (black ginger) extract was used as an anti-inflammatory agent for aphthous ulcers. The FFS could rapidly form a thin film in only 5 s when it was applied to a wet surface e.g. an aphthous ulcer. When the FFS was applied to a dry surface, the FFS without extract could form a film in 2-4 min. The incorporation of this extract contributed to delaying the film-formation time in the dry state; hence, the film-forming time increased to 6-8 min. The mucoadhesive property of FFSs was verified with the wash-off method. To simulate oromucosal conditions, the FFSs were applied on a cellophane membrane coated with mucin and washed by phosphate buffer of pH 6.8. The formulations without mucoadhesive polymers could not withstand flushing with a medium for more than 8 min without dislodging. Therefore, three different mucoadhesive agents were trialed: PVP K90, HPMC E15 LV, and HPC SL. The highest adhesion results were obtained when HPMC was added at 5%(w/w) as well as, the residence time was 22 min. In vitro release of black ginger extract from FFS showed a gradual release for 2 h. This study indicated that the FFS with HPMC E15 LV was an appropriate alternative formulation as a local delivery system for an aphthous ulcer.

Esem Study of Film Formation in Latices Polymerised in Presence of Starch

1998 ◽  
Vol 4 (S2) ◽  
pp. 286-287
Author(s):  
N. Stelmashenko ◽  
A.M. Donald
Keyword(s):  
Lower Cost ◽  
Film Formation ◽  
Environmental Scanning ◽  
The Novel ◽  
Maize Starch ◽  
Waxy Maize ◽  
Glass Slides ◽  
Film Forming ◽  
Industrial Relevance ◽  
Scanning Electron

The Environmental Scanning Electron Microscope (ESEM) was used to study film-formation in vinyl latices polymerised in the presence of varying amount and type of starch. An understanding of the effect of native biopolymers on film forming mechanisms in latex has technological and industrial relevance because it can lead to the creation of novel latices with potentially lower cost and improved biosustainability.Film formation studies were carried out on a range of samples selected by ICI Paints as the most promising candidates for the novel latices. These included vinyl latices polymerised with 2 - 15% of potato and waxy maize starch, taken either in native or modified. Normally, no surfactants were used during latex polymerisation; a few samples were prepared for comparative purposes when polymerisation was carried out both with and without the addition of surfactant. Latex films were spun-cast on glass slides before insertion into the microscope.

scholarly journals Thermal Decomposition of a Single AdBlue® Droplet Including Wall–Film Formation in Turbulent Cross-Flow in an SCR System

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2600
Author(s):  
Kaushal Nishad ◽  
Marcus Stein ◽  
Florian Ries ◽  
Viatcheslav Bykov ◽  
Ulrich Maas ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Relative Velocity ◽  
Pipe Wall ◽  
Film Formation ◽  
Droplet Diameter ◽  
Cross Flow ◽  
Operating Conditions ◽  
Wall Film ◽  
Wall Interaction ◽  
Scr System

The selective catalytic reduction (SCR) methodology is notably recognized as the widely applied strategy for NOX control in exhaust after-treatment technologies. In real SCR systems, complex unsteady turbulent multi-phase flow phenomena including poly-dispersed AdBlue® spray evolve with a wide ranging relative velocity between the droplet phase and carrier gas phase. This results from an AdBlue® spray that is injected into a mixing pipe which is cross-flowing by a hot exhaust gas. To reduce the complexity while gaining early information on the injected droplet size and velocity needed for a minimum deposition and optimal conversion, a single droplet with a specified diameter is addressed to mimic a spray featuring the same Sauter Mean Diameter. For that purpose, effects of turbulent hot cross-flow on thermal decomposition processes of a single AdBlue® droplet are numerically investigated. Thereby, a single AdBlue® droplet is injected into a hot cross-flowing stream within a mixing pipe in which it may experience phase change processes including interaction with the pipe wall along with liquid wall–film and possible solid deposit formation. First of all, the prediction capability of the multi-component evaporation model and thermal decomposition is evaluated against the detailed simulation results for standing droplet case for which experimental data is not available. Next, exploiting Large Eddy Simulation features the effect of hot turbulent co- and cross-flowing streams on the dynamic droplet characteristics and on the droplet/wall interaction is analyzed for various droplet diameters and operating conditions. This impact is highlighted in terms of droplet evaporation time, decomposition efficiency, droplet trajectories and wall–film formation. It turns out that smaller AdBlue® droplet diameter, higher gas temperature and relative velocity lead to shorter droplet life time as the droplet evaporates faster. Under such conditions, possible droplet/wall interaction processes on the pipe wall or at the entrance front of the monolith may be avoided. Since the ammonia (NH3) gas generated by urea decomposition is intended to reduce NOX emission in the SCR system, it is apparent for the prediction of high NOX removal performance that UWS injector system which allows to realize such operating conditions is favorable to support high conversion efficiency of urea into NH3.

A Simple FEM Model for Foil Bearings Under Differential Pressure

2010 ◽  
Author(s):  
Serdar Aksoy ◽  
Mahmut Faruk Aksit ◽  
Yahya Dogu
Keyword(s):  
Film Formation ◽  
Differential Pressure ◽  
Operating Conditions ◽  
Structural Deformation ◽  
Foil Surface ◽  
Film Pressure ◽  
Foil Bearings ◽  
Sealing Capacity ◽  
Wedge Surface ◽  
The Stability

A bump-type foil bearing consists of a compliant corrugated sheet metal supporting structure that is covered by a thin top foil surface. Bumps serve as stiffener and damping elements to increase the stability of the system while top foil creates necessary wedge surface for aerodynamic film formation. Foil bearings are hard to analyze as flexible foil surface deforms and changes shape while aerodynamic film pressure forms. Iterative solutions required typical of EHL analysis. This work utilizes Reynolds Equation to solve aerodynamic film pressure by coupling structural deformation and the fluid film pressure formation. Bearing performance under various operating conditions and the effect of differential pressure boundary condition on sealing capacity is discussed.

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