Lubrication, friction and wear in highly loaded contacts

Elastohydrodynamics

We study lubrication, friction and wear of highly loaded contacts, which operate in the so-called elastohydrodynamic lubrication (EHL) regime. EHL regime is typical for contacts in roller-bearings, gears, cams, etc. Understanding of lubrication, surface texturing, real surface topography and lubricant rheology is a key for reducing the friction losses and extending service life and load capacity of machine parts.

Research characteristics

Elastohydrodynamic lubrication (EHL) is typical for the contacts of non-conformal surfaces that are in relative motion under the presence of lubricant. This lubrication regime leads to the contact stresses up to units of GPa, which leads to a significant elastic deformation of the surfaces and piezo-viscous lubricant behaviour. High-pressure lubricant rheology differs apart from normal conditions. We use numerical methods to solve EHL problems as well. Most of our research is focused on experimental investigation using in-situ optical measurement of lubricant film thickness distribution. For this purpose, we developed worldwide unique experimental method - colorimetric interferometry. Further extension by means of infrared thermography enabled us to study temperature distribution in very thin lubricating films. Lubrication of contacts of low-reflective bodies can be studied by fluorescence microscopy.

Laboratory equipment

  • ball-on-disc tribometer using optical interferometry
  • ball-on-disc tribometer using fluorescence microscopy
  • ball-on-disc tribometer using infrared thermographic camera
  • ball-on-disc tribometer for friction (traction) measurement PCS Instruments MTM2
  • universal pin-on-disk tribometer Bruker UMT Tribolab with heating chamber up to 400°C and high frequency reciprocating module
  • optical profiler Bruker Contour GT X8
  • nanoindenter Hysitron Triboindenter TI 950 with heating chamber up to 800°C

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