ELECTROCHEMICAL-BEHAVIOR OF DIAMOND-REINFORCED COMPOSITES

A diamond-reinforced 1100 aluminum matrix composite (DRC) containing 1 5% by volume of 30 mu m diamond particles was fabricated using standar d powder metallurgy techniques at 600 degrees C. A temperature higher than that required solely for composite consolidation was selected to investigate whether carbide formation occurred. Scanning electron micr ographs and Raman spectroscopy showed no detectable amount of carbide formation. Electrochemical testing showed that the pitting potential o f the composite was the same as that of the pure matrix material, whic h also indicates that either carbides did not form or the amount forme d was so small as not to alter the breakdown potential of the DRC.