Advanced atomization process for metal spray deposition

Spray deposition or spray forming typically utilizes a free-fall atomizer (FFA) with a well established set of capabilities and disadvantages. With the ever-increasing demand for superior products and optimal processing conditions in mass production applications, including automotive parts (e.g., cylinder liners), a close-coupled atomizer (CCA) was studied for spray forming. Compared to the FFA, a CCA requires less gas to produce the same particle velocities with the possibility of increasing these velocities and maintaining gas consumption below that of FFA. By increasing particle velocity, it is believed that higher densities can be achieved under spray conditions with increased solid fraction. In this study, three materials were sprayed: Sri, bearing steel (AISI 52100), and Cu-6wt%Sn, on tubular substrates with diameters of 80mm and 100mm. Results include density measurements, gas consumption trends, surface temperatures, and particle velocities and diameters, obtained with the use of Phase Doppler Anemometry (PDA).