Experimental and Numerical Analyses on the Deposition Behavior of Spherical Aluminum Particles in the Cold Spray Emulated High Velocity Impact Process
Understanding the deposition mechanism of ne solid particles is essential for the effective use of the cold spray (CS) technique, which is used to synthesize dense and thick metallic coatings. As such, in this study, the deposition behaviors of spherical pure aluminum particles were investigated in detail in order to understand the deposition mechanism; these particles had a diameter of 1 mm and were deposited on ve metallic substrate materials, during the CS emulated high velocity impact process. A single particle impact testing system, which is a modi ed single stage light gas gun, was used to evaluate the deposition process. This evaluation con rmed that the critical velocities of Al particles vary signi cantly with the substrate material. In order to identify the dominant factors, the bonding energies, rebound velocities, plastic deformation experienced by the particles and substrates, and removability of the natural oxide lms were evaluated. The results revealed that the critical velocities increased signi cantly with increasing Ar sputtering time required for complete removal of the natural oxide lm; this time represents the removability of the lm. This result con rms that, of the factors considered, the removability of the natural oxide lm exerts the most in uence on Al particle deposition on metallic substrates. [doi:10.2320/matertrans.T M2016803]