Detail publikace

Study of film formation in bovine serum lubricated contacts under rolling/sliding conditions

VRBKA, M. NÁVRAT, T. KŘUPKA, I. HARTL, M. ŠPERKA, P. GALLO, J.

Originální název

Study of film formation in bovine serum lubricated contacts under rolling/sliding conditions

Typ

článek v časopise ve Web of Science, Jimp

Jazyk

angličtina

Originální abstrakt

The aim of this study is to perform a detailed experimental analysis of lubricant film thickness of bovine serum within the contact between the artificial metal and ceramic heads (balls) and the glass disc to analyse the effect of proteins on film formation under various rolling/sliding conditions. Lubricant film observation of bovine serum solutions was carried out using an optical test rig. Chromatic interferograms were recorded with a high-speed CMOS digital camera and evaluated with thin film colorimetric interferometry. Film thickness was studied as a function of time. Under pure rolling conditions, film thickness increases with time as well as with rolling distance for all mean speeds and for both materials of the balls; however the metal ball always forms a thicker lubricating film in comparison to the ceramic ball. Under rolling/sliding conditions, when the disc is faster than the ball, the formation of lubricant film thickness is different compared to pure rolling conditions. At first, film thickness increases rapidly with a rolling/sliding distance for all mean speeds. When maximum film thickness is reached, then this effect is lost and film thickness starts to fall and finally, at the end of the measurement, film thickness drops down to a few nanometres. For the metal ball, maximum values of central film thicknesses are proportional to the mean speed; however this is not observed with the ceramic ball. An absolutely different formation of bovine serum film thickness is observed when the ball is faster than the disc. Under this condition, the protein layer is very thin for both materials of balls, and central film thickness reaches only about a few nanometres. Local protein spots are formed in a very small area of the contact zone and reach the thickness between 20 and 25 nm for the metal ball and 5 nm for the ceramic ball. From the performed experiments under rolling/sliding conditions, it is obvious that the formation of lubricant film thickness is markedly dependent on kinematic conditions acting in the contact, especially on the positive and negative slide-to-roll ratio and the mean speed. In addition, the material of the artificial head has a certain influence on the formation of bovine serum lubricating film.

Klíčová slova

Artificial hip joint, metal and ceramic ball, bovine serum, protein formation, lubrication, film thickness, colorimetric interferometry, rolling/sliding conditions

Autoři

VRBKA, M.; NÁVRAT, T.; KŘUPKA, I.; HARTL, M.; ŠPERKA, P.; GALLO, J.

Rok RIV

2013

Vydáno

7. 1. 2013

Nakladatel

SAGE Publications Ltd

Místo

Velká Británie

ISSN

1350-6501

Periodikum

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY

Ročník

227

Číslo

5

Stát

Spojené království Velké Británie a Severního Irska

Strany od

459

Strany do

475

Strany počet

17

BibTex

@article{BUT96677,
  author="Martin {Vrbka} and Tomáš {Návrat} and Ivan {Křupka} and Martin {Hartl} and Petr {Šperka} and Jiří {Gallo}",
  title="Study of film formation in bovine serum lubricated contacts under rolling/sliding conditions",
  journal="PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY",
  year="2013",
  volume="227",
  number="5",
  pages="459--475",
  doi="10.1177/1350650112471000",
  issn="1350-6501"
}