Author: Donald W. PetrasekPublisher:
ISBN:
Category : Fibers
Languages : en
Pages : 36
Book Description
Metallurgical and Geometrical Factors Affecting Elevated-temperature Tensile Properties of Discontinuous-fiber Composites
Author: Donald W. PetrasekPublisher:
ISBN:
Category : Fibers
Languages : en
Pages : 36
Book Description
Metallurgical and Geometrical Factors Affecting Elevated-temperature Tensile Properties of Discontinuous-fiber Composites
Author: Donald W. PetrasekMetallurgical and Geometrical Factors Affecting Elevated Temperature Tensile Properties of Discontinuous Tungsten Fiber Reinforced Composites
Author: D. W. PetrasekPublisher:
ISBN:
Category : Composite metallurgy
Languages : en
Pages : 27
Book Description
The length to diameter ratio and orientation of the fibers in discontinuous fiber reinforced composites was correlated to their elevated temperature tensile properties. Composites were made of copper and copper - 2 per cent chromium alloy reinforced with tungsten fibers having various length to diameter ratios. The composites were tested in tension at 300, 900, and 1500 F. These results were then compared with continuous length fiber reinforced composites containing the same matrix materials and fiber contents. The fiber orientation in the composite was found to be extremely critical at elevated temperatures. Shear failures occurred for specimens tested at 1500 F in which the fibers were misaligned from the tensile axis by as small as 3 deg. Composites which failed in shear had significantly lower tensile strengths than did composites having fibers aligned parallel to the tensile axis of the specimen. Tensile strengths of discontinuous fiber reinforced composites in which the fibers were aligned parallel to the tensile axis were dependent upon the length to diameter ratio of the fibers in the composite. As the length to diameter ratio of the reinforcing fibers decreased, the tensile strengths of the composites decreased. Alloying the copper matrix with chromium increased the matrix shear strength which was beneficial even though the alloying element reacted with the fiber. Load transfer from the matrix to the fiber was dependent upon the shear strength of the matrix. The greater the shear strength, the higher the load transfer capabilities of the matrix. The tensile strength of copper - 2 per cent chromium matrix composites thus was higher than unalloyed copper matrix composites having the same fiber content and the same length to diameter ratio fibers.
Government-wide Index to Federal Research & Development Reports
Author: Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1078
Book Description
Monthly Catalog of United States Government Publications
Author: NASA Technical Note
Author: Scientific and Technical Aerospace Reports
Author: Nuclear Science Abstracts
Author: Metal Matrix Composites
Author: C.T. LynchPublisher: CRC Press
ISBN: 1351082892
Category : Science
Languages : en
Pages : 181
Book Description
The concept of reinforcing a material by the use of a fiber is not a new one. The Egyptian brick layer employed the same principle more than three thousand years ago when straw was incorporated into the bricks. More recent examples of fiber reinforced composites are steel-reinforced concrete, nylon and rayon cord reinforced tires, and fiberglass reinforced plastics. In the last several years considerable progress has been made on new composite structures particularly utilizing boron (on tungsten substrate) fibers in various matrices. Many of these advances have been reviewed recently by P. M. Sinclair1 and by Alexander, Shaver, and Withers.2 An excellent earlier survey is available by Rauch Sutton, and McCreight.3 Boron-reinforced epoxy composites are being fabricated and tested as jet engine components, fuselage components, and even as a complete aircraft wing because of the tremendous gain in experimentally demonstrated properties such as modulus, strength, and fatigue resistance, particularly on a weight normalized (e.g., strength/density) basis. Other than glass/epoxy and boron/ epoxy composites and perhaps boron/aluminum, the systems now under study are in the early stages of research and development. These include other boron/metal composites, graphite/polymer, graphite/metal, graphite/graphite, alumina/metal, and aligned eutectic (directionally, solidified) combinations. As Sinclair points out, designers are wary about filamentary composites becausethere is little background information and scant experience.
Author: