Carbon fiber reinforced silicon carbide, so called C/C-SiC materials, were manufactured via Fiber Patch Placement (FPP). At FPP an unidirectional fiber tape is cut into defined pieces, so-called patches, and placed on a negative mold by a robot gripper. The structure of the patched carbon fiber reinforced polymer (CFRP) is typically realized with the help of a thermoplastic binder located on the bottom side of the patch. The binder melts due to a heating wire installed in the gripper during placement and provides the necessary fixation of the individual patches after cooling. The preform created in this way is then infiltrated with a resin. The great advantage of this process is that each patch can be placed independently to other patches in position and direction. This provides a high degree of flexibility and allows the production of load-path optimized and reproducible 3D components. The main disadvantage, on the other hand, is that a gap is formed between two adjacent patches due to the discontinuous fiber. This gap is the weakest link in the composite and must be compensated via an optimized lay-down pattern of the individual patches across all layers.

In this study, two-dimensional C/C-SiC plates are manufactured via a three-step liquid-silicon-infiltration process (LSI), which consists of CFRP fabrication, pyrolysis, and silicon infiltration. The primary goal is to demonstrate that patched CFRP components can be successfully converted to a ceramic matrix composite (CMC). This is done by adjusting the material and the process parameters under the continuous analysis of the state of the material by scanning electron microscopy and µ-computed tomography. Furthermore, the mechanical properties are investigated with the focus on the influence of discontinuous fiber reinforcement due to the patches. Tensile tests are used to characterize and compare the mechanical properties of continuous fiber reinforced and patched C/C-SiC.