Fiinctioiuil Area Problems. Opportunities, and Constraints 35 



missile developers to consider those materials to achieve 

 significant performance gains. Carbon fiber-reinforced 

 plastics provide the very high strength and, especially, the 

 stiffness needed for such applications as aircraft wing 

 components, helicopter blades, and other highly loaded 

 structures. Used in such applications, they can cut 

 weights by 15-30 percent, greatly simplify design and 

 construction, increase reliability, reduce production 

 costs, and decrease fuel consumption. 



Carbon fiber-reinforced carbon composite materials are 

 also the most effective substances yet discovered for such 

 extremely high temperature applications as ballistic mis- 

 sile reentry body nose tips and rocket nozzle throats. With 

 further development, the materials are expected to be- 

 come useful as high-temperature turbine blades for cruise 

 missile engines. In addition to the performance gains 

 possible with carbon/carbon composites, their domestic 

 availability and potential low cost could make them at- 

 tractive alternatives to high-cost gas turbine superalloys. 

 Inasmuch as the superalloys contain substantial amounts 

 of cobalt and chromium for which the United States is 

 almost totally dependent on imports, the development of 

 carbon/carbon composites as alternatives could relieve 

 U.S. dependency on foreign sources. 



Fiber-reinforced metallic materials, referred to as met- 

 al-matrix composites, have a variety of potential military 

 applications, such as helicopter transmission housings, 

 portable bridging components, strategic missiles, mines 

 and torpedoes, tactical missiles, airframe and gas turbine 

 components, and satellite components. In addition, the 

 materials show promise in the future for such uses as laser 

 mirrors, lightweight gun mounts, submarine propellers, 

 and radar antennas. 



One of the early results of the Department of Defense 

 research and development program in metal-matrix com- 

 posites is a fiber-reinforced lead grid material for sub- 

 marine batteries that can lengthen the submanne battery 

 replacement cycle from 5 to 10 years, thereby aligning it 

 with the nuclear core replacement schedule and reducing 

 maintenance costs appreciably. Another significant con- 

 sequence of the work is the potential substitution of metal- 

 matrix composites for such critical materials as chro- 

 mium, cobalt, titanium, and beryllium. For example, it 

 has been determined that composites consisting of high- 

 modulus graphite fiber-reinforced magnesium alloys ex- 

 hibit stiffness, strength, and dimensional stability equiv- 

 alent or superior to beryllium at the same weight. 



During fiscal year 1982, the Department of Defense 

 will move vigorously into the area of rapid solidification 

 technology. The objective of the new technology is to 

 produce very high quality starting materials for new fam- 

 ilies of aluminum and titanium alloys and superalloys. 

 Current modest investments have demonstrated sufficient 

 promise and maturity of the technology to justify initiat- 

 ing a major, long-term financial commitment to accelerate 

 the development of the new materials. 



Rapid solidification technology involves solidifying 

 metals and alloys from a molten state at a very fast rate, 

 leading to the possibility of alloys with superior high- 

 temperature strength, vastly improved corrosion resist- 

 ance, and increased lifetime. For example, a new super- 

 alloy has been made that can run 100°C hotter in jet 

 engines, thereby offering the design flexibility of either a 

 15 percent thrust increase or a dramatic reduction in fuel 

 consumption. A new aluminum alloy has been developed 

 that is 30 percent lighter for aircraft construction. In the 

 future the new alloys could enable airplanes to either carry 

 30 percent more pay load or decrease fuel consumption. 



During the next 5 years the Department of Defense's 

 rapid solidification technology program will involve basic 

 research, exploratory development, specific technology 

 demonstrations, and manufacturing technology efforts to 

 be conducted at university, industrial, and government 

 laboratories. The technology emerging from that thrust is 

 expected to provide major economic benefits to transpor- 

 tation, space, and energy systems and to the U.S. com- 

 mercial manufacturing base in general. 



AERONAUTICAL TECHNOLOGY 



The integration of advanced electronics and materials 

 technologies is leading to significant improvements in the 

 combat capability of tactical aircraft. It will soon be 

 possible to maximize aircraft performance by automat- 

 ically changing the shape of key aircraft components in 

 flight such as wing sweep, airfoil camber, and engine 

 inlets; to provide independent six-degree-of-freedom con- 

 trol to increase agility and minimize weapon delivery 

 errors; and to integrate the flight, fire control and naviga- 

 tion systems. Those advances will provide task-tailored 

 handling qualities. Fire control information will be used 

 to automatically or semiautomatically assist the pilot in 

 maneuvering the aircraft. Additionally, the new control 

 concepts provide the capability to conduct a maneuvering 

 approach to launch for air-to-ground weapons, thereby 

 increasing survivability against ground defenses. 



Recent investigations of the Department of Defense's 

 aircraft engine development programs have concluded 

 that additional efforts need to be placed on durability and 

 reliability aspects during the early research and develop- 

 ment phases of the program. The technology program is 

 also being reoriented to stress reliability and main- 

 tainability. The increasing costs of propulsion systems 

 and the supporting costs after they are placed in operation 

 have become major concerns. Since a large cost factor is 

 the number of parts in a propulsion system, current efforts 

 are aimed at reducing the number of compressor stages by 

 improving component performance. A major effort in the 

 advanced turbine engine gas generator program is being 

 made to increase the structural testing of promising new 

 turbine engine concepts. Successful completion of those 



