EFFECT OF NOZZLE DIAMETER AND ATOMIZING AIR PRESSURE ON CHARACTERISTICS OF IN-FLIGHT PARTICLES IN WIRE ARCSPRAYING

In wire arc spraying, the atomizing air pressure and applied nozzle system areimportantfactors influencing particles characteristics and coating quality. the aim ofthis paper isto study how the characteristics ofparticles such as size, velocity and temperature are influencedby the operating conditions in wire arc spray. for that, three types ofwires are tested: solid wireof stainless steel 316l, cored wires 97mxc and 98mxc. arc spray gun is an arc jet 9000manufactured by tafa. for each condition, the particles temperature and particles velocity aremeasured using an imaging ccd camera, spray watch (oseir ltd). particles size distributionsare determined with a laser grain meter. the morphology and composition of particles wereevaluated with sem, edx and x-ray diffraction. results induce important modifications in theparticles size distributions and particles velocity. a small diameter nozzle and high atomizing airpressure resulted in a reduction in particles size distributions and an increase in particles velocity.