|
6453 |
|
Friday, June 12, 2020, Hall K2 9:00 AM Maritime Industry & Corrosion Protection |
|
Fabrication of cavitation erosion resistant bronze coatings by thermal and kinetic spraying for maritime applications |
|
Michél Hauer / Fraunhofer Institute for Large Structures in Production Engineering IGP, Thermal Joining Engineering, Germany Frank Gärtner* / Helmut Schmidt University of the Federal Armed Forces, Germany Sebastian Krebs/ Helmut-Schmidt University, University of the Federal Armed Forces Hamburg - Material Science, Germany Werner Krömmer/ Linde AG Linde Gases Division, Germany Knuth-Michael Henkel/ University of Rostock, Chair of Joining Technology, Germany |
|
The present study describes prerequisites for the application of cavitation resistant bronzes by applying different coating techniques, such as cold spraying, HVOF spraying, warm spraying and arc spraying. By optimization to best cavitation resistance, the deposited coatings can increase the service life of ship rudders significantly and even serve in repair processes for ship propellers. As guideline for process selection optimum coating properties, as achieved by the different spray techniques, are evaluated in comparison to those of bulk materials as shipbuilding steel and highly cavitation erosion resistant nickel aluminum bronze. For comparison, the process descriptions and parameter sets described in this work aim at coating flat structures and a typical coating thickness in the range of 300 to 600 µm. The investigated spray techniques could provide a cavitation resistance that meets the requirements with respect to applications on ship rudders. By using high-pressure warm spraying and cold spraying, properties similar to those of cast nickel aluminum bronze were achieved, however at relatively high costs. In contrast, coatings produced by using HVOF and arc spraying have erosion rates that are only about four respectively three times higher as compared to cast nickel aluminum bronze, while far outperforming bulk shipbuilding steel. Hence, their properties should be sufficient for acceptable service life or docking intervals for ship rudder applications. In summary, particularly with respect to costs, HVOF and arc spraying therefore represent a good compromise to reach acceptable coating properties. |