During the 1960s, research on protective coating materials at NASA?s Lewis Research Center demonstrated that a class of polymers known as condensation polymides could be fabricated into lightweight fiber reinforced plastics. These materials were capable of withstanding temperatures up to 600o F for thousands of hours but were not initially easily utilized. Lewis researchers, led by Dr. Tito T. Serafini, perfected an improved polymide composition that eliminated inconsistent chemistries, use of hazardous solvents, and other process/structural problems.
The material, called PMR-15, reacts chemically to form a reinforced plastic that is highly resistant to heat and oxidation. Ferro Corporation and ICI Fiberite cautiously applied the material to a few selected ?hot? sections of aircraft structures and engine components. As these applications accumulated flight time, designers gained more confidence in PMR-15 and the number of uses increased. GE Aircraft Engines pioneered this effort by producing PMR-15 advanced composite prepregs (fiber and resin blankets) for aircraft and jet engine applications. With a lightweight, low-cost substitute for titanium, these prepregs enabled jet engine manufacturers to significantly improve engine thrust-to-weight ratios without sacrificing structural integrity. At present, PMR-15 advanced composite materials are used by all of the major jet engine manufacturers. More recently, PMR-15 has been applied in aluminum strip processing, steel mills and finishing lines as self-lubricating composite wear liners and bushings used in high heat, high friction areas such as valve seats, wheels, pulleys, and insulators. Lasting ten times longer than its predecessor, aluminum bronze, and needing no grease, this durable and rugged material is bound to find many other commercial applications.