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Previous George D. Graffin Lecturers in Carbon Science and Engineering

The American Carbon Society supported by grants from the Asbury Graphite Mills, Inc., sponsors this lecture series in North American Universities in honor of George D. Graffin, a pioneer in the natural graphite industry. Each year the Society selects a lecturer who has made distinguished contributions to carbon science and engineering. The lecture is available to North American universities, by arrangement with the lecturer. Additional information may be found at the Society's web site at

Dr. Neil Murdie
Research Scientist
Honeywell Aircraft Landing Systems
3520 Westmoor Street
Plant 25
South Bend, IN, U.S.A.
phone: (219) 231-2852
fax: (219) 231-2853

The Use of Carbon-Carbon Composites in Aircraft Braking Applications

C-C composites are used in a wide variety of applications including aircraft brakes, automobile brakes, rocket nozzles, as well as structural materials in the aerospace industry.  The largest current market for C-C composites is their application as the heat-sink and friction material for aircraft brakes. Today, carbon brakes are used on most wide-body commercial aircraft and the majority of military aircraft.

In aircraft braking applications carbon-carbon composites fulfill three functions including:

a) Heat sink - The C-C composite friction material acts as the heat sink to convert the kinetic energy of the aircraft into heat.  The friction material must dissipate this heat slowly to prevent melting of nearby metal structures.  Carbon is an attractive material because the heat capacity of carbon is 2.5 times greater than that of steel.

b) Friction - Sufficient friction must also be generated by the brake lining material to bring the aircraft to a smooth, controlled stop under different kinetic energy conditions (taxi, landing and RTO).

c)  Structural member - High mechanical strength is also required at elevated temperatures since the friction material also acts as the structural member and transfers the frictional torque to the wheel during braking applications.  The strength of carbon is comparable to that of steel, while at high temperatures, carbon is nearly twice as strong.

The lecture describes why carbon-carbon composites are used as friction materials.  It discusses the important properties of C-C composites as related to their use as the friction material in aircraft brake applications.  The friction and wear mechanisms of carbons and the influence of carbon structure, physical, thermal, mechanical and chemical properties as well as friction films on the performance of C-C friction materials used in aircraft braking applications are described.

Proposed Visits:

  • Michigan State University
  • Southern Illinois University-Carbondale
  • Alfred University
  • Oak Ridge National Labs.
  • University of Newcastle upon Tyne
  • Los Alamos National Labs.
  • Clemson University
  • Notre Dame University
  • Purdue University