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TY - THES AU - Schulz, Marvin TI - Metallisch dichtende Beschichtungen im Armaturenbau VL - 79 PB - RWTH Aachen University VL - Dissertation CY - Düren M1 - RWTH-2024-03413 SN - 978-3-8440-9430-5 T2 - Schriftenreihe Oberflächentechnik SP - 1 Online-Ressource : Illustrationen PY - 2024 N1 - Druckausgabe: 2024. - Auch veröffentlicht auf dem Publikationsserver der RWTH Aachen University N1 - Dissertation, RWTH Aachen University, 2023 AB - In almost all industrial sectors, valves are used for the regulation of various media flows, which is why the valve production is one of the most important economic sectors in Germany. However, the valve market is highly competitive. New types of coatings offer the possibility to increase economic efficiency and competitiveness. In this thesis, two concepts are presented for increasing the economic efficiency and competitiveness through the development of thermally sprayed valve coatings. On the one hand, solid lubricants are integrated into established wear protective coatings that are commonly used in valves, and on the other hand, valve coatings that require less post-processing steps are developed. Valves are usually controlled by an actuator, whereby energy is lost in the form of heat during each switching operation. By integrating graphite and hexagonal boron nitride, friction and wear are reduced compared to conventionally used valve coatings. By the use of powders with a finer particle size distribution, near-net-shape coatings have been developed in which the necessary surface quality is achieved by direct polishing, without the need for the cost-intensive grinding process. Abrasion resistance tests show that the developed coatings have a higher wear resistance than conventionally used valve coatings. In the case of solid lubricant containing coatings this increased resistance is attributed to the reduction of shear stresses due to the solid lubricants and in the case of the fine powder coatings due to the higher cohesion of the coating and the more finely dispersed carbides. Electrochemical corrosion, erosion and cavitation tests show that the integration of solid lubricants reduces these resistances. The reason for this is the low cohesion of the solid lubricants and the additionally introduced paths at which the electrolyte can infiltrate the coating. However, a sufficient resistance can be achieved through a process development and the integration of finer solid lubricants. Due to the dense coating structure, the near-net-shape coatings exhibit a higher resistance to erosion, cavitation and corrosion compared to conventionally used valve coatings under the investigated test conditions. A demonstrator test qualified the most promising solid lubricant containing coating for the use in the valve industry. LB - PUB:(DE-HGF)11 ; PUB:(DE-HGF)3 DO - DOI:10.18154/RWTH-2024-03413 UR - https://publications.rwth-aachen.de/record/983416 ER -