Effect of Iron and Silicon Content on Stress Corrosion Cracking in a Thermomechanically Processed Aluminum Alloy.

摘要

A study of stress corrosion cracking in 7475 type aluminum alloy plates was conducted using five iron and silicon levels, chromium and zirconium minor additions, and two tempers: T651 and thermomechanical processing (TMP). The T651 specimens showed no clear effects of purity or minor addition on stress corrosion resistance; however, a large purity effect was seen in TMP specimens. As total iron and silicon content decreased from 0.31 to 0.02 weight percent, the 2000-hour threshold stress intensity about doubled in these alloys. In addition, TMP alloys showed a relationship between stress corrosion, threshold stress intensity, and precracked Charpy toughness. (Author)