The WAAMpeller was fabricated from a Nickel Aluminium Bronze alloy at Rotterdam Additive Manufacturing LAB, in the Port of Rotterdam. The prototype 3D printed propeller represents a steep learning curve of the understanding of material properties.
“This is because 3D printed materials are built up layer by layer,” says Kees Custers, Project Engineer in Damen’s R&D department. “As a consequence, they display different physical properties in different directions – a characteristic known as anisotropy. Steel or casted materials, on the other hand, are isotropic – they have the same properties in all directions.”
Because of this critical difference, one of the first steps was to carry out extensive testing of the material properties of the printed material to ensure compliance to Bureau Veritas standards.
“The challenge has been to translate a 3D CAD file on a computer into a physical product. This is made more complex because this propeller is a double-curved, geometric shape with some tricky overhanging sections,” explains Mr Custers.
“Material characterization and mechanical testing have been an important part of this project,” says Wei Ya, Postdoctoral Researcher from the University of Twente at RAMLAB. “We have to make sure that the material properties meet the needs of the application. Material toughness, for example – ensuring that the propeller is able to absorb significant impact without damage.”
This first prototype WAAMpeller will be used for display purposes, while production of a second propeller with class approval is expected to commence later next month.