Localized Corrosion Induced in Graphite/Aluminum Metal-Matrix Composites by Residual Microstructural Chloride

Abstract

Graphite/Aluminum (G/Al) metal-matrix composites (MMCs) manufactured using the titanium-boron vapor deposit (Ti-B VD) method were found susceptible to localized corrosion in chloride-free sodium sulfate solutions in which Al should be passive. Corrosion behavior of G/Al MMC precursor wires and plates made of diffusion-bonded packs of precursor wires was investigated in this study. In chloride-free sodium sulfate solutions, severe pitting of the wire- wire diffusion bonds was observed to coincide with distinct pitting regimes in anodic polarization diagrams of the G/Al MMC plates. The pitting of the diffusion bond regions disbonded the precursor wires, and caused the plates to exfoliate. Pitting was found to be induced by residual microstructural chloride, which originated from the Ti-B VD method. This work suggests that the exfoliation of G/Al MMC plates should be eliminated by producing composites with halide-free microstructures.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1990
Accession Number
ADA219861

Entities

People

  • L. H. Hihara
  • R. M. Latanision

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Anodic Polarization
  • Aqueous Solutions
  • Chemical Analysis
  • Chemical Engineering
  • Chemistry
  • Classification
  • Composite Materials
  • Corrosion Resistance
  • Engineering
  • Epoxy Composites
  • Materials
  • Materials Processing
  • Materials Science
  • Metal Matrix Composites
  • Microscopes
  • Military Research
  • Security

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Reinforced Composite Materials