Residual stress in cold spray additively manufactured titanium cylinders

Cold spray additive manufacturing (CSAM) is a solid-state deposition process that can produce 3D objects using metal powder as the feedstock material. Severe and localised plastic deformation allows the metal particles to bond each other after impacting a solid surface when travelling at supersonic speeds in a gas jet. The magnitude of the plastic deformation depends on the materials properties which in turn can also be influenced by the process parameters used in the CSAM process. In this sense, the residual stress state after the deposition process can also be altered by changing process conditions to minimise and avoid distortion and fracture. For this reason, it has been investigated the effect of two critical parameters in the process such as traverse speed and deposition rate on the residual stress state in titanium cylinders produced by CSAM. The residual stresses were mapped using neutron diffraction in the full 2D cross-section of the cylinders along the radial and axial direction. It was found that the magnitude of the residual stresses decrease when increasing the traverse speed, but increase when increasing the deposition rate.