Mechanical and Aerospace Engineering

Multifunctional materials demonstrate a combination of functionality, adaptability and survivability for a variety of engineered applications. We have developed one kind of novel multifunctional ceramic composites which is reinforced with a high volume fraction (60%) of aligned carbon nanotubes (CNTs). Unique material properties are listed as:

• Material composition: 60 vol.% of CNT and 40 vol.% of SiCN
• High surviving temperature: up to 1000 Celsius degree
• Sustainability in harsh environment: oxidation, hot-corrosion environment, water vapor and acid fume.
• Flexibility: can be bent to 100% of the original length and the flexibility testing can be repeated for 1000 times without any crack or performance degradation.
• Low density: 2.1 g·cm-3
• thermal conductivity in room temperature:
  • in-plane: 7.2 W/(m·K))
  • through-thickness: 2.0 W/(m·K))
• In-plane electrical conductivity: 3.22×10e6 S/m
• Tensile strength: 538 MPa
• Young’s modulus: 118 GPa

With such unique multifunctional properties, the material can be used for stringent harsh environments, such as liquid-fueled rocket engine combustion devices (thrust chambers and nozzles), aircraft brakes, etc.. It can also be suitable for surface coatings on curved surface on hypersonic vehicles for thermal management.

 

 

Figure 3. (a) Flexibility test of the multifunctional ceramic composite thin film. The sample can be bent with two ends touching each other; (b) Tensile strength comparison under flexibility test.