Suspension Thermal Spraying – a novel procedure enters industrial operation
Lower surface roughness and higher microstructure homogeneity demonstrate the advantages of suspension sprayed coatings over conventional powder sprayed coatings. The suspension spraying technology applies finely dispersed sub-micro-sized and nanoscale powders rather than coating powders with particle sizes of 5 to 50 µm. Up to now, hardware components for suspension spraying have only been available on a laboratory scale. The Fraunhofer IWS Dresden presents system components, necessary for the conversion of industrial spraying facilities to the suspension technology at the Hannover Messe Industrie for the very first time.
For the suspension spraying technology hardware components, e.g. suspension feeder and a suitable injector, are necessary. The special suspension feeder unit guarantees constant feed rates and high process stability. With feed rates from 5 to 100 ml min -1 coating deposition efficiencies of 70 % can be achieved.
In addition to the suspension feeder, the scientists of the Fraunhofer IWS Dresden have developed injectors for plasma- and HVOF spraying technologies. These can thus be successfully adapted to the available plasma spraying booths, e.g. F 6 and Delta as well as to the TopGun HVOF spraying unit. We are now able to offer complete conversion kits, combined with modified hardware components, for the suspension spraying technology. Consequently this technology can now be integrated into existing spraying equipment with minimum effort.
Suspensions must show high homogeneity, low viscosity and long-term stability in order to meet high quality and process stability-essential requirements for industrial applications. Suspensions with a solid content of 5 - 70 mass % can be fabricated by the dispersion of finely-dispersable powders. Since preferably water is used as dispersion medium, it can be secured that the equipment will not corrode and that there will be no additional safety and environmental protection demands.
The Fraunhofer IWS offers a comprehensive range of services for suspension thermal spraying technologies, including:
- development of hardware components and conversion kits for suspension thermal spraying
- suspension testing at customer’s request and development of tailored suspensions
- development and analysis of coating solutions covering the chain from material to the coated component
- customer support during implementation and system integration
Our scientists are looking forward to welcoming you at Hannover Messe Industrie, Hall 6, Booth A30, April 7 - 11, 2014.