Metallurgical Characterization of the Interfaces and the Damping Mechanisms in Metal Matrix Composites.

Abstract

High inherent damping is a material property requirement to meet the need for dynamic dimensional precision and weight savings in space structures. A preliminary investigation indicates that MMC exhibit improved damping with respect to conventional structural alloys of aluminum or titanium. In the present investigation, a graphite-aluminum composite (P55/6061) has been selected to study the microstructural features and mechanisms responsible for damping in MMC. During this investigation, methodology to measure damping by clamped free flexure and uniaxial tension-tension test techniques were developed. Work conducted within the reporting period: (1) Preliminary results with free-free flexure indicate that this method can be used sucessfully to measure damping in metal matrix composites; (2) TEM of Gr/Al composites show that the dislocations adjacent to the fiber matrix interface are thermal expansion mismatch of th fiber and matrix during the fabrication process; (3) Strain amplitude dependent damping is the result of dislocation motion and correlates well with the Granato-Lucke theory of dislocation damping.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1986
Accession Number
ADA173470

Entities

People

  • Mohan S. Misra

Organizations

  • Martin Marietta

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Aluminum
  • Aluminum Alloys
  • Amplitude
  • Ceramic Materials
  • Composite Materials
  • Dislocations
  • Electron Microscopy
  • Experimental Data
  • Frequency
  • Materials
  • Materials Processing
  • Materials Testing
  • Measurement
  • Metal Matrix Composites
  • Metals
  • Test Methods
  • Transmission Electron Microscopy

Readers

  • Materials Science and Engineering.
  • Reinforced Composite Materials
  • Structural Dynamics.

Technology Areas

  • Space