|
5291 |
|
Thursday, June 08, 2017, Hall 27 9:00 AM Suspension Spraying II |
|
Microstructural characteristics and performances of Cr2O3 and Cr2O3-15%TiO2 SHVOF-coatings obtained from water-based suspensions |
|
Filofteia-Laura Toma* / Fraunhofer IWS, Germany Nick Kulissa / Fraunhofer Institute IWS, Germany Annegret Potthoff/ Fraunhofer Institute IKTS, Germany Robert Kratzsch/ Fraunhofer Institute IKTS, Germany Christoph Leyens/ Fraunhofer Institute IWS; Technische Universität Dresden, Germany |
|
Cr2O3 coatings and Cr2O3-based binary coatings offer high hardness, excellent sliding wear performance and corrosion resistance. Therefore, they are widely used for applications in the paper and textile industry, pumps and mechanical sealing systems. Compared to the conventional spray processes, the technology of Suspension-HVOF (high velocity oxy-fuel flame spraying of suspensions, S-HVOF) using submicron-scaled raw feedstock materials allows the production of dense, finely structured coatings with smooth surfaces and improved mechanical properties. This work proposed investigations of the microstructure and performance of Cr2O3 and Cr2O3-15wt.%TiO2 coatings obtained by S-HVOF with water-based suspensions. For the development of the binary composition two routes were used to produce ready-to-spray suspensions: i) dispersion of an appropriate alloyed material in the solvent and ii) mixture of two stable suspensions in the desired ratio. The resulting properties of the S-HVOF coatings (microstructure, phase composition, microhardness, E-Modulus and corrosion resistance performance) were evaluated and compared to that of conventional APS and HVOF coatings. From the experimental results it was observed that the suspension sprayed coatings showed in most of cases denser microstructure, higher mechanical properties and superior corrosion performances when compared to coatings produced from feedstock powder. |