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4878 |
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Wednesday, May 11, 2016, Room 3E 3:00 PM Suspension Spraying II |
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Investigation of the corrosion, wear and erosion performances of HVOF-Cr2O3 sprayed coatings obtained from aqueous suspensions |
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Filofteia-Laura Toma* / Fraunhofer IWS, Germany Annegret Potthoff / Fraunhofer IKTS, Germany Stefan Makowski/ Fraunhofer IWS, Germany Daniel Eichner/ Technische Universität Dresden, Germany Christoph Leyens/ Fraunhofer IWS, Germany |
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Chromium(III) oxide is a widely used coating material for applications in the printing, paper and textile industry, in pumps and mechanical sealing systems, due to its high hardness, excellent sliding wear performance, corrosion resistance. Suspension-HVOF spraying (S-HVOF) allows development of dense, finely structured coatings with smooth surfaces and improved mechanical properties. In this work the investigation of corrosion, wear and erosion resistance of Cr2O3 coatings obtained by S-HVOF process with aqueous suspension is proposed. The performance of the S-HVOF sprayed Cr2O3-coatings were compared to that of conventional APS coatings. The coatings were sprayed with and without bond coat on corrosion-resistant steel substrates. The corrosion performance of the coatings was tested in 1N H2SO4 media at 85°C for 300 hours. The wear resistance was investigated via oscillating ball-on-flat tests at room temperature using Al2O3 and 100Cr6 balls as counter parts at a load of 25 N and an oscillating frequency of 10 Hz. The solid particle erosion tests were carried out with erodent particles (glass, alumina) at different impingement angles varying from 30° to 90°C. The SHVOF-Cr2O3 coatings produced from aqueous suspensions disposed of denser microstructure with high mechanical stability (> 1200 HV0,3). From the experimental results it was observed that the suspension sprayed coatings showed in most of cases superior corrosion, wear and erosion performances when compared to the conventional APS coatings. |