Student Research Projects, Papers

Topic

Manufacturing of C/C Composites: Influence of Fillers and Pressure Application in the SPS Process

Description

Carbon fibre reinforced carbon (C/C) are high-temperature materials with a density below 2 g/cm³ and outstanding specific mechanical properties. When used in a protective gas atmosphere or vacuum, they can withstand operating temperatures exceeding 2000 °C. A well-established method for producing C/C composites is the Polymer Infiltration and Pyrolysis process (PIP), which can be divided into three manufacturing steps. In the first step, a carbon fiber reinforced plastic (CFRP) is produced. This is followed by a pressurless pyrolysis, during which the polymer matrix is converted into carbon (C/C) at temperatures of up to 1500 °C. This process, however, leads to significant crack formation. The incorporation of additives into the polymer matrix can significantly influence the crack structure and the resulting properties of the C/C composites. This study aims to systematically investigate and evaluate the effects of graphite and silicon as fillers on the microstructure and properties of fabric-reinforced C/C composites using two different resin systems. In addition, selected compositions of the C/C composites will undergo Spark Plasma Sintering (SPS) post-treatment in order to analyze their pyrolysis behavior under applied pressure. The investigations can alternatively also be carried out using short fibres.

Working programme:

• Literature review on the state of science and technology with a focus on:
  • Processes and matrix systems for C/C production
  • Possible additives for C/C manufacturing
• Planning and execution of experimental work (sample production, pyrolysis, and SPS heat treatment)
• Composite characterization (physical, microstructural, and mechanical)
• Documentation of results
• Preparation and presentation of the scientific thesis