Implementation of Innovative Manufacturing Technologies in Foundries for Large-Volume Components

The development of new manufacturing technologies opens up new perspectives for the production of propellers (diameter < 5 m), especially since the use of the established sand casting process as a technology is only partially competitive in today’s market. Therefore, different applications of generative manufacturing methods for the implementation into the production process were investigated. One approach is the mould production using additive manufacturing processes. Investigations showed that especially for large components with high wall thicknesses available systems and processes for sand casting mould production are cost-intensive and conditionally suitable. With our development of a large-format FDM printer, however, the direct production of large-format positive moulds for, for example, yacht propellers up to 4 m in diameter is possible. Due to the comparatively low accuracy requirements for the mould, the focus is on the durability of the drive system and the rigidity of this FDM printer. Equipped with simple linear technology in portal design and cubic design of the frame structure with rigid heated print bed, the aim is to achieve maximum material extrusion via the print head. The production of plastic models not only facilitates handling during the moulding process, but also allows considerable time and cost savings to be made during the running process. A further step in our development is the direct production of the components using WAAM. A possible concept for robot-supported build-up welding for the production of new innovative propeller geometries is presented using the example of a hollow turbine blade for a tidal power plant.

Reversing Design Methodology of Ceramic Core for Hollow Turbine Blade Based on Measured Data

The precision of complex ceramic core is one of the essential factors for hollow turbine blade manufacturing, which has a significant impact on the development of the modern aircraft engine. In terms of the low precision of ceramic core formation, this paper proposes an approach through measuring the data from a group of ceramic cores, to study the computational methods for displacement field, deformational feature decoupling, and structural shrinkage ratio. Based on modeling and analysis of decoupled deformational features and the uneven structural shrinkage ratio, this paper proposes an inverse design method and optimizes the design of the die profile for ceramic core. The applicability of this method is validated using numerical simulation data and experimental results.