A novel spiral trajectory for damage component recovery with cold spray

Cold spray is widely applied for the dimensional recovery of damaged parts and components due to the advantages in avoiding local melting, depressing thermal stress and oxidation, and high bonding strength. In this work, a novel trajectory applicable to cold spray for repairing damaged workpiece was proposed for the purpose of improving productivity and reducing cost in machinery work. The Archimedean spiral was chosen as the basis for building this novel trajectory due to the constant distance between two successive turns. This novel trajectory was composed of two symmetrical Archimedean spirals adapted to the damage contour by scaling method. Nozzle speed at each target point was compensated based on the corresponding crater depth. With this novel trajectory, the experimental validation of an A15056 coating depositing on a damaged Al2027A substrate was conducted. The results showed that the damaged workpiece was perfectly repaired and the coating had good quality in terms of porosity and bonding strength. Therefore, cold spray with the spiral trajectory and adapted nozzle speed is an effective way to repair damage components. Comparing with the round-trip trajectory, Archimedean spiral trajectory is able to significantly save process duration as well as consumption of powder and spray system energy, which leads to the increase of spray efficiency. (C) 2016 Elsevier B.V. All rights reserved.