Accession Number : ADA234322


Title :   Corrosion of Graphite Aluminum Metal Matrix Composites


Descriptive Note : Technical rept. 1 Mar-31 Dec 1990


Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MATERIALS SCIENCE AND ENGINEERING


Personal Author(s) : Buonanno, M A ; Latanision, R M ; Hihara, L H ; Chiang, J F


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a234322.pdf


Report Date : Feb 1991


Pagination or Media Count : 17


Abstract : Several commercial G/Al 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 G/Al MMCs. Large scale G/Al model MMCs were fabricated at MIT in order to study the corrosion behavior of G/Al 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 G/Al galvanic couple. Ion implanting the surface of G/Al model MMCs with zinc, a cathodic inhibitor, did reduce the corrosion G/Al galvanic couple; however, the protection was incomplete.


Descriptors :   *ALUMINUM OXIDES , GALVANIC CORROSION , IONS , CORROSION , PROCESSING , THEORY , RATES , GRAPHITE , COOLING , COATINGS , ELECTRODES , MIXING , MICROPROBES , IMPLANTATION , SCANNING , COUPLING(INTERACTION)


Subject Categories : Laminates and Composite Materials


Distribution Statement : APPROVED FOR PUBLIC RELEASE