Complex Inspection of Sliding Friction Pairs to Determine Metrological and Tribological Characteristics
Jānis Lungevičs, Armands Leitāns, Ernests Jansons

Description of the Technology

Research begins with measurement of the surface textures using Taylor Hobson Form Talysurf Intra 50 profilometer to get 3D image (model) of sliding friction pair. The created model includes components such as surface shape deviation, waviness and roughness (see. Fig. 1).
 
Fig. 1. Material surface 3D image.
 
Each component can be individually separated from 3D image, thus allowing the assessment of the nature of the surface, isotropy level, and even the type of mechanical treatment. More than 20 different 3D roughness parameters can be obtained from the 3D image to characterize the studied surface. In addition, it is possible to get the measured surface photo simulation images that are equivalent to the optical microscope images (see. Fig. 2).
 
Fig. 2. Material surface photo simulation.
 
Further investigation of the sliding friction coefficient is found out using certified ball-on-disc type CSM Instruments TRB-S-EE-0000 tribometer. During the measurement curve is obtained, that shows friction coefficient values in time and allows to assess whether the process is stable. The curve also allow to determine the components run-in time.
 
And lastly, wear resistance study is carried out. Long lasting wear test is completed by tribometer and after that decaying material cross-sectional area is measured using profilometer (see. Fig. 3.)
 
Fig. 3. Decaying material cross-sectional area.
 

The results of wear resistance calculation allows to evaluate the investigational component durability under normal operating conditions. Combining all research results the customer gets comprehensive and experimentally based information on operational characteristics of the sliding friction pairs and expert recommendations for further improvements.



Applications

The complex testing of sliding friction pairs is usable in any industry facing the parts wear, especially if technical equipment contains components with complex shapes whose production is costly and replacement complicated. Examples include: air transport; rail transport; hydroelectric stations, thermoelectric stations, etc. The method can be successfully applied in equipment inspection and diagnostics process.



Advantages

Complex research of sliding friction pairs is performed by experienced technicians, using modern and standardized research facilities. All experiment settings and methodology are individually planned for each particular case to obtain performance evaluation of sliding friction pairs and prognoses according to the customer request. Customer get important information on the operational characteristics of material and may assess whether:

  • friction pair is energy efficient;
  • the life of the selected material will be long enough.

The experts are able to offer efficient solutions that improve the functioning of friction pairs.



Keywords

coatings,3D surface,sliding friction,friction coefficient,wear,wear rate,microtopography

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