Recent work by the author1 has shown that when fatigue testing unnotched Ti-8Al specimens at low stress levels in methanol/HCl stress corrosion attack occurs along slip bands. This attack is secondary to other stress corrosion processes, namely intergranular and cleavage fracture, which also occur during the fatigue process.
The purpose of this note is to illustrate the fracture which results from slip band attack in more detail than presented previously,1 and to avoid confusion, as in the past,2 between this kind of attack and cleavage fracture. In addition, a rationale for the overall fracture process is presented.
Figure 1 shows the appearance of slip band attack and fracture as observed by scanning electron microscopy. At A, localized attack has resulted in notches and grooves into grain boundary facets. At B, transgranular fracture has occurred through a grain which has suffered extensive attack along slip bands. This kind...
