Abstract
Systematic fatigue crack deviations have been observed in samples of textured Ti-6Al-4V plate under some conditions where the fracture plane is not a plane of symmetry in the texture. Observations on the plastic zone around the crack tip show that this is asymmetrical, and that the crack deviates as a result of the disparity in slip activity. The results may be rationalized in terms of the operation of easy, <a>, slip and hard, <c+a>, slip on the two sides of the growing crack.