High Temperature Microwave Absorption Materials

(Video link #1)

This project is to develop one kind of ceramic composite for electromagnetic (EM) absorption application at high temperature (>700oC). Typical EM absorption materials are composed of high concentrations of iron powders in polymer matrix, however are heavy and costly. Carbon materials, such as carbon nanotubes (CNTs), carbon black, graphite flakes, have also been studied for low temperature applications (< 500oC) thanks to their electrical conductivity and light weight. For higher temperature (>700oC) and oxidizing environment, traditional carbon/polymer matrix composites are no longer applicable. Current technology is lacking of a solution to supply a suitable material system with the desired properties in such harsh environment. The desired properties under high temperatures are listed as:

  • good oxidation resistance
  • appropriate electrical conductivity
  • appropriate magnetic permeability

This project is to develop ceramic composites having the above characteristics and can sustain at high temperature and harsh environment, e.g., airplane nozzle, wing tip, nose cone, etc. The manufacturing technique is based on ultra-high temperature ceramics (UHTCs) and polymer-derived ceramics (PDC). The fabricated ceramic composites have a wide EM absorption bandwidth covering the whole R band (26.5–40 GHz).