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1307 |
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Monday, June 02, 2008, Auditorium 2 11:30 AM Automotive Coatings on cylinder liners and piston fire faces, testing of coatings and means of surface preparation for inner diameter coatings |
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Plasma transferred wire arc spraying of novel wire feedstock onto cylinder bore walls of AlSi engine blocks |
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Thomas Schläfer* / RWTH Aachen University, Surface Engineering Institute, Germany Kirsten Bobzin / RWTH Aachen University, Surface Engineering Institute, Germany Felix Ernst/ RWTH Aachen University, Surface Engineering Institute, Germany Jochen Zwick/ RWTH Aachen University, Surface Engineering Institute, Germany Frank Schreiber/ Durum Verschleiss-Schutz GmbH, Germany Alexander Schwenk/ GTV Verschleiss-Schutz GmbH, Germany Mareike Hahn/ University of Duisburg-Essen, IPE, Materials Science and Engineering, Germany Clemens Verpoort/ Ford Research Center Aachen GmbH, Germany Gerhard Flores/ Gehring GmbH & Co. KG, Germany |
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Hypoeutectic AlSi engine blocks of modern passenger cars are generally equipped with cast iron liners in order to provide cylinder running surfaces that meet the tribological requirements. A very promising alternative to the use of cylinder liners lies within the application of thermally sprayed coatings onto the walls of cylinder bores as friction partner for the piston rings. This work describes the development of a novel iron based wire feedstock as well as its application by the Plasma Transferred Wire Arc internal diameter coating system. The material developed within the frame of this work leads to partially amorphous coatings with embedded nanoscale precipitations if processed by thermal spraying. The coatings were applied onto the inner diameters of test liners made of Aluminium EN AW 6060 and onto cylinder bore walls of in-line 4 cylinder engines. All substrates were mechanically roughened in order to obtain high bond strengths of the sprayed coatings. The coatings microstructure was analysed by light optical microscopy, hardness measuring and transmission electron microscopy. Furthermore the oil storage capacities of the honed surfaces were determined and friction testing was carried out. |