| Autor: |
Portnoi, K., Timofeeva, N., Zabolotskii, A., Sakovich, V., Trefilov, B., Levinskaya, M., Polyak, N. |
| Zdroj: |
Soviet Powder Metallurgy & Metal Ceramics; 1981, Vol. 20 Issue 2, p116-119, 4p |
| Abstrakt: |
To ensure that the necessary bond strength at fiber/matrix interfaces is attained during the manufacture of a carbon-aluminum composite such as that investigated in this work, the degree of chemical reaction between the components must be strictly controlled, the optimum amount of the reaction product (AlC) being 2-3%. For matrices of other compositions and fibers of other types, the optimum AlC content may be different. A bond at a fiber/matrix interface forms mainly as a result of 'mechanical' joining of the components by carbide phase particles, which leads to the appearance at this interface of numerous micro-channels capable of acting as paths of mass (e.g., water) transport into the main volume of material. The corrosion of a carbon-aluminum composite material is a consequence of the occurrence of two processes - decomposition of the AlC and anodic dissolution of the aluminum in contact with the carbon. The decomposition of the aluminum carbide weakens the bond between the components by increasing the volume of reaction products, which in turn mechanically damages the fibers and induces cracking in the matrix, i.e., intensifies crevice corrosion. The corrosion resistance of a carbon-aluminum composite can be enhanced on the one hand by decreasing the amount of the carbide phase without adversely affecting the strength of the bond between the components (e.g., by suitable choice of matrix composition and fiber type) and, on the other, by preventing electrical contact being made between the matrix and fibers. The most effective method of achieving both ends simultaneously is to use carbon fibers with protective coatings. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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