Tribologically Tailored Cylinder Liner with Machined Microstructures

• Applicants: Professor Dr.-Ing. Berend Denkena; Professor Dr. Friedrich Dinkelacker; Professor Dr.-Ing. Adrian Rienäcker
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering ; Hydraulic and Turbo Engines and Piston Engines
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 276357669

Within the DFG Research Group Microstructuring of Thermo-Mechanically Highly Stressed Surfaces fundamental knowledge concerning the dimensioning, manufacturing and the tribological properties of friction-lowering microstructures was investigated. Experimental tests using a single cylinder research engine showed in particular a high potential of microstructures manufactured by means of a cutting process. Cylinder liners that were equipped with those microstructures showed lower frictional losses and emissions resulting from the lubricant as long as the microstructuring was carried out regarding the tribological demands of the different liner surface areas (tailored cylinder liners). Due to the fact that up to 60% of the complete frictional losses of an engine are related to the piston assembly group, microstructured liners will lead to a substantial reduction of the fuel consumption and therefore of CO2 und unburned hydrocarbon emissions. By the advent of this technology in the field of combustion engines, an important contribution to securing the world climate could be made. Beside the reduction of frictional losses, tailored cylinder liners could enhance the oil film formation on the liner surface and lead consequently to lower wear and tear and lower oil consumptions. A main characteristic of cylinder liner surfaces is the diversity of the tribological stress depending on the piston position in the work cycle. Therefore, it is essential that the microstructures are carried out by varying their geometrical properties and patterns along the liner surface in order to meet the tribological demands in the best possible way. The objective of this project is the development of tailored cylinder liners for the reduction of friction, wear and oil consumption of internal combustion engines. By investigating these liners under realistic engine conditions, the transfer of this technology into the industrial application can be achieved. The consortium of this project consists of 3 university institutes and an industrial partner. The experimental engine tests will be carried out at the Institut für Technische Verbrennung (ITV, Hannover), the tribological properties and layout will be determined aby the Institut für Maschinenelemente und Konstruktionstechnik (IMK, Kassel) and the customized cutting manufacturing process will be realized by the Institut für Fertigungstechnik und Werkzeugmaschinen (IFW, Hannover). As one of the most important manufacturer of heavy-duty engines, the MTU Friedrichshafen (Rolls-Royce Power Systems AG) will be the industrial partner.

• DFG Programme: Research Grants (Transfer Project)
• Application Partner: MTU Friedrichshafen GmbH