COLD GAS DYNAMIC SPRAY APPARATUS, SYSTEM AND METHOD

摘要

A system for cold gas dynamic spraying of particulate material has a de Laval nozzle and two or more radial particle inlets located between the throat and the outlet of the nozzle, the two or more particle inlets arranged symmetrically around a linear flow path of the nozzle. Blocking of the inlets is reduced by controlling pressure of particle carrier gas to provide a stable particulate material injection pressure before and during introduction of working gas into the nozzle, and/or by clearing the particle inlets of residual particles after a spraying process. Such a system and associated method combines benefits of both downstream and upstream cold gas spray systems. Further, a nozzle for spraying particulate material having a cross-sectional shape that is narrower in a middle section compared to edge sections provides coatings with superior cross-sectional profiles.