Simulation of friction and wear in DLC/steel contacts for different loading histories and geometries: Ball-on-plate configuration and piston–cylinder-contacts

Abstract

DLC-coatings are commonly used in industry as a wear protective layer and as a solid lubricant for highly loaded tribological contacts. In order to evaluate the wear performance of different DLC-coatings under unlubricated oscillating sliding wear conditions and to validate the reliability of coated components, many wear-tests with simple model-geometries as well as expensive endurance-tests with the real application conditions have to be performed. This is because the transfer of the wear results to different contact conditions (variation of load, application geometry) is not yet possible. In an earlier paper a novel unified dissipated energy model for the ball-on-plate-geometry was developed and its transferability to different types of coatings was verified. In this paper the model was applied to different load steps and a piston-cylinder-geometry in order to verify its generality. The analytical wear calculation tool-the Global Incremental Wear Model (GIWM)-was revised by considering different load steps and by implementing a new approach for the calculation of wear in the piston-cylindercontact. Based on the good agreement between the experimental results and both wear and friction simulations, the validity of the unified wear model regarding its transferability to different loading histories and geometries was successfully proven.

Influences of the Flow Speed and the Micro-Texture Deepness on the Hydrodynamic Lubrication Characteristics

“…Predictions of the friction coefficient and the wear depth, which were obtained from a Global Incremental Wear Model "GIWM," are in good agreement to experiments and successfully validate the transferability of the model. 3 A numerical simulation was done with different fluid speeds to determine the flow characteristics (shear stress, pressure) on different faces of micro-asperities; 4 a theoretical method was also used to find the approximated micro-asperities dimensions. 5 The use of textured surfaces with different shapes of micro-cavities (textures) and at different locations of the texture zone can be an effective approach to improve the performance of bearings.…”

Influences of the Textured Surface Micro-Texture Depth on the Friction Coefficient

“…A nanostructure superhydrophobic surface that minimizes the liquid-solid contact area so that the liquid flows predominantly over a layer of air had been engineered [2], the surface has demonstrated dramatic slip effects: a slip length of ~20 mm for water flow had been also found. Predictions of the friction coefficient and the wear depth, which were obtained from a Global Incremental Wear Model "GIWM", are in good agreement with experiments and successfully validate the transferability of the model [3]. A numerical simulation was done with different fluid speeds to determine the flow characteristics (shear stress, pressure) on different faces of micro-asperities [4]; a theoretical method was also used to find the approximated micro-asperities dimensions [5].…”

Dry sliding wear system response of ferritic and tempered martensitic ductile iron

“…Ducom TR-208-M1 Ball on plate type wear monitor [14][15][16][17] with specimen as flat plate and a spherical tipped diamond cone of 120° angle 0.4mm tip diameter was used in order to investigate the wear system response of the as-cast heat treated specimens. The mechanism of Ball on plate wear test is very much similar to that of Pin on disc wear tester.…”