MEASUREMENT OF BRONZE PARTICLES VELOCITY IN FLOW FROM THE COLD SPRAYING EJECTOR NOZZLE

Read more The experimental dependence of spherical aluminum bronze microparticles Metco 51F-NS (mean particle size 44 μm, Oerlikon Metco, USA) in flow from the axially symmetric ejector nozzle with a central body on the stagnation pressure determined by a nozzle configuration with keeping constant vacuum at the central body cutoff. It is found that the dependence has an extremum in which derivative sign changes distinguishing ejector nozzles from the typical de Laval nozzles used in cold gas-dynamic spraying. It was shown in reference experiments that the maximum values of the microparticles velocity from the experimental ejector nozzle are close to the velocity values of such particles in the flow from the Laval nozzle corresponding to the stagnation pressure values. The obtained results open wide prospects to use ejector nozzles with a central body and open-type powder feeders in cold gas-dynamic spraying.

Keywords:
ejector nozzle with a central body, de Laval nozzle, spherical microparticles velocity, three-pulse shadow method, cold gas-dynamic spraying. 
УДК 621.793

MEASUREMENT OF BRONZE PARTICLES VELOCITY IN FLOW FROM THE COLD SPRAYING EJECTOR NOZZLE