Comparison of Reacted Film Formation of Three Different Types of Perfluoropolyethers with a Heated Steel Surface

1998 ◽  
Vol 41 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Masabumi Masuko ◽  
Norikatsu Kamio
Keyword(s):  
Steel Surface ◽  
Film Formation ◽  
Different Types

Atomization of Liquids by Means of a Rotating Cup

1950 ◽  
Vol 17 (2) ◽  
pp. 145-153 ◽  
Author(s):  
J. O. Hinze ◽  
H. Milborn
Keyword(s):  
Working Conditions ◽  
Drop Size ◽  
Film Formation ◽  
Angular Speed ◽  
The State ◽  
Experimental Results ◽  
Drop Formation ◽  
Dimensionless Groups ◽  
Different Types ◽  
Centrifugal Action

Abstract Liquid, supplied through a stationary tube to the inner part of a rotating cup widening toward a brim, flows viscously in a thin layer toward this brim and is then flung off, all by centrifugal action. The flow within this layer and the disintegration phenomena occurring beyond the brim have been studied, experimentally as well as theoretically. A formula has been derived for the thickness and for the radial velocity of the liquid layer within the cup, which proved to agree reasonably well with experimental results. Three essentially different types of disintegration may take place around and beyond the edge of the cup designated, respectively, by: (a) the state of direct drop formation; (b) the state of ligament formation; and (c) the state of film formation. Which one of these is realized depends upon working conditions. Transition from state (a) into (b), or of state (b) into state (c) is promoted by an increased quantity of supply, an increased angular speed, a decreased diameter of the cup, an increased density, an increased viscosity, and a decreased surface tension of the liquid. The experimental results have been expressed in relationships between relevant dimensionless groups. For the state of ligament formation a semiempirical relationship has been derived between the number of ligaments and dimensionless groups determining the working conditions of the cup. Results of drop-size measurements made for the state of ligament formation as well as for the state of film formation show that atomization by mere rotation of the cup is much more uniform than commonly achieved with pressure atomizers.

Effects of a thickener structure on grease elastohydrodynamic lubrication films

2000 ◽  
Vol 214 (4) ◽  
pp. 327-336 ◽  
Author(s):  
M Kaneta ◽  
T Ogata ◽  
Y Takubo ◽  
M Naka
Keyword(s):  
Film Thickness ◽  
Direct Observation ◽  
Film Formation ◽  
Elastohydrodynamic Lubrication ◽  
Rolling Speed ◽  
Molecular Structures ◽  
Optimum Temperature ◽  
Oil Viscosity ◽  
Base Oil ◽  
Different Types

The effects of the thickener structure and base oil viscosity on the grease film formation in rolling point elastohydrodynamic contacts have been discussed on the basis of direct observation using the optical interferometry technique. Three different types of diurea greases without additives have been used as test greases. As the base oils three kinds of ether-type synthetic oils having similar molecular structures but different viscosities were used. The film behaviour of fresh greases has also been compared with that of the degraded greases. It has been found that the behaviour of grease elastohydrodynamic lubrication films is basically influenced by the thickener structure and base oil viscosity. The adhesion or deposition of the thickener on the contacting surfaces and oil starvation which affect film formation depend on the thickener structure, base oil viscosity and rolling speed. Furthermore, it has been suggested that there is an optimum temperature which gives a maximum film thickness according to the consistency of the grease.

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.

scholarly journals Characteristic features of Enterococcus faecalis film formation on the stainless steel AISI 321 depending on the surface roughness

2018 ◽  
Vol 20 (90) ◽  
pp. 58-62
Author(s):  
K. U. Kravcheniuk
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Enterococcus Faecalis ◽  
Steel Surface ◽  
Film Formation ◽  
High Density ◽  
Initial Number ◽  
Steel Aisi ◽  
Aisi 321 ◽  
Stainless Steel Aisi

At the present stage of milk products manufacture, the most important factor affecting their safety and reducing their storage time is a microbiological one. Despite all complex of measures including washing, disinfection, heat processing to eliminate microbes on production equipment and in the finished products it is very difficult to achieve good results. This deals with the fact that microorganisms can survive on the production equipment thanks their ability to form biofilms and also treatment-resistant microorganisms strains appear in the process of continuous sanitary treatment. The aim of the paper was to study the biofilms Enterococcus faecalis formation on the stainless steel AISI 321 depending on their initial quantity and surface roughness. The plates made of the stainless steel AISI 321of surface roughness Rа = 0.955 mkm, Rа = 0.63 mkm and Rа = 0.16 mkm were used for the investigation. It  was found that during 9 hours Enterococcus faecalis was forming the biofilms of weak density less than 0,5 units on the stainless steel surface of AISI 321 of roughness Rа = 0.955 mkm. After the 12th hour the intensive film formation process was noticed in the options with initial number of cells E.f from 2000 to 10 000 and 20–50 thousand/ cm2, the biofilm was getting of high density – 1.246 and 1.415 respectively with initial number of cells less than 1000 per 1 cm2 of steel surface and it was of medium density – 0.672 cells. The process of film formation on the steel surface of roughness 0.63 mkm was rather decelerating, in comparison with the surface of roughness 0.955 mkm. Though, despite this, in the options with initial number of E.f. cells from 2000 to 10 000 and 20–50 thousand/cm2 the biofilms were of high density after the 12th hour of incubation, i.e. it was the same as for the  surface of 0.955 mkm roughness.  The process of film formation at such initial numbers of E.f. on the surface of roughness 0.63 mkm was finishing after the 24th hour while at roughness 0.955 mkm – after the 18th hour of incubation. It was found that on the steel surface of roughness 0.16 mkm the process of film formation was greatly getting slower comparing to the surfaces of roughness 0.955 and 0.63 mkm. During 12 hours of E.f. incubation in case when the initial number of E.f. was less than 1000 per 1 cm2 the film was of weak density but in cases when the initial number was 2000 – 10 000 and 20–50 thousand/cm2 the biofilms were of medium and high density – 0.917 and 1.025 units. After 18 hours of incubation the film was of medium density only in case when the initial number was less than 1000 E.f. per 1 cm2 of the surface. At larger initial number of bacteria it was of high density. Only after 24 hours of E.f. incubation biofilms in all options were of high density. Thus, we came to the conclusion that E.f. biofilms formation on the stainless steel AISI 321 is influenced by the surface roughness and initial number of bacteria. The results have shown that on the plates of roughness 0,16 mkm the film formation process is slower than on the surface of roughness 0.955 and 0.63 mkm.

scholarly journals Effects of WC Particle Types on the Microstructures and Properties of WC-Reinforced Ni60 Composite Coatings Produced by Laser Cladding

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 583 ◽  
Author(s):  
Pengxian Zhang ◽  
Yibin Pang ◽  
Mingwei Yu
Keyword(s):  
Stainless Steel ◽  
Uniform Distribution ◽  
Laser Cladding ◽  
Steel Surface ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Composite Coatings ◽  
304 Stainless Steel ◽  
Stainless Steel Surface ◽  
Different Types

WC-reinforced Ni60 composite coatings with different types of WC particles were prepared on 304 stainless steel surface by laser cladding. The influences of spherical WC, shaped WC, and flocculent WC on the microstructures and properties of composite coatings were investigated. The results showed that three types of WC particles distribute differently in the cladding coatings, with spherical WC particles stacking at the bottom, shaped WC aggregating at middle and lower parts, with flocculent WC particles dispersing homogeneously. The hardnesses, wear resistances, corrosion resistances, and thermal shock resistances of the coatings are significantly improved compared with the stainless steel substrate, regardless of the type of WC that is added, and especially with regard to the microhardness of the cladding coating; the addition of spherical or shaped WC particles can be up to 2000 HV0.05 in some areas. Flocculent WC, shaped WC, and spherical WC demonstrate large to small improvements in that order. From the results mentioned above, the addition of flocculent WC can produce a cladding coating with a uniform distribution of WC that is of higher quality compared with those from spherical WC and shaped WC.

Effects of transversely oriented defects and thickener lumps on grease elastohydrodynamic lubrication films

2001 ◽  
Vol 215 (3) ◽  
pp. 279-288 ◽  
Author(s):  
M Kaneta ◽  
H Nishikawa ◽  
M Naka
Keyword(s):  
Film Thickness ◽  
Contact Area ◽  
Surface Defects ◽  
Film Formation ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Optical Interferometry ◽  
Transient Behaviour ◽  
Different Types

Using the optical interferometry technique, transient behaviour of grease films at an elastrohydrodynamic lubrication (EHL) point contact caused by a transversely oriented groove and long bump passing through the contact area is directly observed with three different types of diurea grease without additives. The effects of the thickener content on the grease film formation are also examined. It has been found that the behaviour of EHL films depends strongly on the thickener structure, and the effects of surface defects on EHL films become pronounced as the film thickness decreases. It has also been found that the thickener lumps move through the EHL conjunction while repeating attachment to the surfaces and detachment from them, and the thickener lumps deposited on the surfaces affect the film behaviour as a kind of solid bump.

THE EFFECT OF COPPER ION ON THE FILM FORMATION RATE OF TITANIUM-BASED NANOCERAMIC LAYER ON A MILD STEEL SURFACE

2019 ◽  
Vol 26 (03) ◽  
pp. 1850165
Author(s):  
ALIREZA GHANBARI ◽  
MOHAMMAD REZA POURHOSSAINI
Keyword(s):  
Mild Steel ◽  
Steel Surface ◽  
Film Formation ◽  
Steel Substrate ◽  
Formation Rate ◽  
Copper Ion ◽  
Polarization Technique ◽  
Effect Of Copper ◽  
Dc Polarization ◽  
Mild Steel Substrate

In this study, the effect of copper ion (Cu[Formula: see text]) was investigated on the film formation rate of Ti-based nanoceramic conversion layer on a ST12 type mild steel. At the first step, the film formation properties of the Ti conversion layer were characterized using DC polarization technique and FE-SEM micrographs. In the next step, concentration of Cu ion was optimized in the Ti solution bath, and finally, the rate of Ti ion (Ti[Formula: see text]) consumption in the conversion solution bath, with and without Cu ion, was detected by spectrophotometric technique using a dye-metal indicator. It was revealed that the addition of Cu ion to the Ti solution bath could increase the precipitation rate of Ti-based compounds on the mild steel substrate, leading to increment of film formation rate of the conversion layer.

Electrochemical Study of the Passivation and Passive Film Breakdown of Mg70 Zn30 Metallic Glass

1986 ◽  
Vol 80 ◽  
Author(s):  
Patrick L. Hagans
Keyword(s):  
Phase Transition ◽  
Metallic Glass ◽  
Passive Film ◽  
Film Formation ◽  
Protective Film ◽  
Peak Potential ◽  
Peak Current Density ◽  
Film Breakdown ◽  
Different Types ◽  
Dc Polarization

AbstractAnodic dc polarization measurements of glassy Mg70 Zn30 in pH=9.3 boric-borate electrolyte with and without the presence of Cl− were used to study both passive film formation and breakdown. In the absence of C− a single, broad passivation peak is observed which is very similar to that found with triply distilled Mg except that the large increase in peak potential and reduction in peak current density indicates that a more stable film has formed on Mg70 Zn30. Also observed with Mg70 Zn30 but not with Mg, Zn or other different types of crystalline Mg alloys is a large, narrow peak in the transpassive region (i.e., the region where the passive film begins to break down and/or O2 evolution commences). This process of breakdown of the passive film and further oxidation of the base metal is totally irreversible and is almost completely missing on the second and subsequent voltage sweeps. Although speculative in nature, existing evidence suggests that a phase transition has occurred within the passive film itself. In the presence of Cl− this process does not occur as passive film breakdown is initiated via a pitting mechanism at a potential nearly 2.5 Volts more negative than the onset of O2 evolution. Nevertheless, the onset of pitting is still 0.4 Volts more positive than that found for Mg indicating again that a much more protective film has formed on Mg70 Zn30

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