CMC for resource savings and reduction of CO2 emissions
In the field of aviation, weight reduction and energy efficiency are at the top of the list of requirements - also for new materials and components. Ceramic fiber composites (CMC) offer significant advantages for use in aircraft gas turbines: CMC components are only one-third as dense as conventional metal components, so they contribute to a significant reduction in weight. They can also be used at temperatures up to 300 K higher. In the hot section of gas turbines, CMC components therefore enable more efficient and complete combustion, save fuel and thus reduce CO2 emissions. Oxide ceramic composites (O-CMC) also naturally offer high oxidation resistance and a low tendency to corrosion in the combustion atmosphere, thus increasing the service life of the components.
Since the beginning of 2021, the Fraunhofer Center HTL has been working as part of the "AirfOx" project, funded by the Bavarian aerospace program BayLu25, to develop an automation-capable process and technologies that will enable near-net-shape production of engine blades for aircraft gas turbines (airfoils) from oxide ceramic fibers in an integral and series-production-ready manner.
Textile processing of ceramic fibers into near-net-shape 3D preforms for greater resource efficiency
By using multiscale simulation and CAD programs for load-oriented fiber design, the Airfoil example will be used to demonstrate how the development of a complex 3D preform can proceed in CMC manufacturing. Innovative weaving techniques will be used to develop a new manufacturing method for three-dimensional fabric preforms made of ceramic reinforcing fibers for CMC components with cover surfaces of different lengths, while at the same time allowing support structures in the form of webs to be woven in. Locally occurring stress peaks, which are detected during modeling, can also be taken into account in the fabric design. Transferring textile 3D weaving techniques to ceramic fibers is a particular challenge due to their brittleness. With the special manufacturing technology, the textile-ceramic 3D preforms are produced near-net-shape in one piece. This ensures high resource efficiency in the manufacturing process.
In the project, a digitization concept for the production of the preform is being developed in order to continuously record and evaluate the production data, which are essential for the component properties, during the weaving implementation of the textile semi-finished product. The aim is to set up a data management system as a preparatory measure for certifications to ensure the traceability of all process parameters, thus facilitating subsequent aviation certification.
The textile semi-finished product is converted into a CMC component in four steps, with the special process for infiltration being used for the first time for this type of 3D preform. In addition to the technology development of the infiltration process, the focus is on the automatability of the process.
"AirfOx" makes automated manufacturing steps of CMC components possible.
CMC airfoils can significantly contribute to reducing fuel consumption and lowering CO2 emissions. " AirfOx" will make a significant contribution here towards series production and should pave the way for establishing the new resource-efficient technology for manufacturing complex 3D fiber prefoms for CMCs, which can then also be used for other CMC types, e.g. SiC/SiC-CMC.
Fraunhofer Institute for Fraunhofer ISC - Center for High Temperature Materials and Design HTL, Application Textile Center Fiber Ceramics
Prof. Dr.-Ing. Frank Ficker # Kulmbacher Straße 76 # 95213 Münchberg
Frank.firstname.lastname@example.org # Phone: +49 (0)175 1137192