Interface Character of Aluminum-Graphite Metal Matrix Composites.
Abstract
The results of the research described in this annual report can be summarized in terms of the experimental approaches used. The materials studied included the commercial 6061 VSB 32 composites as well as layered model systems on single crystal and polycrystal-line graphite substrates and glassy carbon substrates. The I/V characterization of the interface demonstrated that the oxide within the interface plays a major role in the interface strength. If the interface was in a low conductivity state, fracture occurred at the interface weaving though the oxide. When the interface was switched into an electrically conductive state, fracture occurred within the single crystal graphite substrate. The interface strength was directly correlatable with its conductivity state. AES was used to identify the fracture path and the chemistry of the model laminate. TEM of the commerical materials and the model laminates again showed the presence of gamma-Al2O3, MgAl2O3 and TiB2 in the as-prepared samples. No aluminum carbide was found. To make sure the carbide was not dissolved during the thinning a non-aqueous methanol based etching solution was used. When samples were aged within the solid state region, Al4C3 and Al4C4O were found. Their growth was strongly dependent on the heat treat environment, the temperature, and the crystallography of the graphite relative to the interface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 27, 1982
- Accession Number
- ADA110787
Entities
People
- Harris L. Marcus
Organizations
- University of Texas at Austin