Anisotropy of fatigue crack growth in wire arc additive manufactured Ti-6Al-4V

The effects of crack growth direction on the fatigue crack growth of wire arc additive manufactured Ti-6Al-4V were studied. The fatigue crack growth rate (FCGR) of horizontal and vertical samples has different stress intensity factor transition point, Delta K-T, which is 11.3 MPa m(1/2) and 10.3 MPa m(1/2), respectively. The FCGR of vertical sample is 5% higher than that of horizontal sample when the stress intensity factor, Delta K is smaller than Delta K-T. The difference in FCGR is resulted from the microstructure characterization and the fatigue crack growth direction.