Electrochemical Behavior of AlB.sub.12-AlN Composites in Natural Environments

Electrochemical processes occurring on ceramic AlB.sub.12-AlN composites induced by polarization in a 3% NaCl aqueous solution at 37°C are examined for the first time. Aluminum dodecaboride AlB.sub.12 is found to dissolve so slowly that it hardly influences the composites' corrosion resistance in actual environments. A higher aluminum nitride amount in the composite increases its electrochemical corrosion resistance. The electrochemical behavior of aluminum dodecaboride and ceramic nitride composites generally allows the materials to retain their service properties in natural corrosive environments even at 37°C.