INFLUENCE OF SMALL ADDITIONS OF ZINC ON THE NATURE OF THE GRAIN BOUNDARY PRECIPITATES N AN A A 8090 ALLOY

摘要

Several studies have shown that the morphology and the chemistry of thegrain boundary precipitates have considerable adverse effects on the stressf corrosion cracking (SCC) resistance of most A.l-Li based alloys (I -6). The general notion is that the stress corrosion crack initiation in such alloys occurs due to the anodic dissolution of the grain boundary precipitates (1-6). The implication is that an improyeinent in the SCC resistance of such alloys can be brought about by either suitably modifying the chemistry or altogether changing the type of the grain boundary precipitates.