Three-Dimensional Residual Stress Mapping of AFSD Ti-6Al-4V Using Multi-Plane Contour Method Measurements

Additive friction stir deposition (AFSD) is a solid-state additive manufacturing process capable of rapid, large-scale metal deposition. Compared with powder fusion-based additive manufacturing methods, AFSD eliminates solidification-related defects, can join traditionally non-weldable materials, has lower feedstock cost, and has 5-10 times greater build rates. However, the severe thermomechanical deformation inherent to AFSD leads to complex residual stress evolution that can influence build distortion and final component geometry. In this work, residual stress distributions in an AFSD Ti-6Al-4V single-track “L”-shaped build were experimentally characterized using the contour method. Four cut planes were analyzed, enabling reconstruction of the internal stress state at multiple locations and providing insight into the evolution of residual stress with build height and throughout the deposited volume. The results of these experiments will be discussed in the context of integrity of large-scale AFSD builds, sensitivity to geometric features, and determination of manufacturing requirements.