Corrosion of Graphite Aluminum Metal Matrix Composites
Technical rept. 1 Mar-31 Dec 1990
MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MATERIALS SCIENCE AND ENGINEERING
Pagination or Media Count:
Several commercial GAl MMCs have been studied by potentiodynamic polarization in deaerated 0.5 M Na2SO4. The results have been compared with those which were predicted by the mixed electrode theory. The results indicate that processing conditions, especially the cooling rate, had a strong influence on the corrosion behavior of the GAl MMCs. Large scale GAl model MMCs were fabricated at MIT in order to study the corrosion behavior of GAl galvanic couples with the scanning potential microprobe SPM. Preliminary results indicate that coating graphite with discontinuous alumina did not reduce the corrosion rate of the GAl galvanic couple. Ion implanting the surface of GAl model MMCs with zinc, a cathodic inhibitor, did reduce the corrosion GAl galvanic couple however, the protection was incomplete.
- Laminates and Composite Materials