Kinetic Deposition of Ti Coatings Using Gas Atomized Ti Powder Particles

Abstract

Abstract The kinetic spray process is a coating process that involves impingement of a substrate by metallic particles at high velocities. In this work, we investigated the kinetically sprayed Ti coatings, which were deposited onto different metallic substrates using gas-atomized powders. The powder particles were characterized in terms of size distribution, morphology, hardness, and explosibilty index. The propellant gas used for coating deposition was compressed nitrogen. The substrates were placed inside an enclosure filled with nitrogen gas during deposition. It was observed that Ti coatings can be deposited at relatively high deposition efficiencies using large particles (median size~ 100 mm). Ti coatings with a wide range of thickness and good macroscopic appearance were readily prepared. The particle temperature appears to have strong effects on the coating formation; deposition efficiencies of ~90% were achievable. Microscopic examination of the coatings revealed deposited Ti particles with significantly lower deformation when compared to ductile materials such as Al and Cu. As a result, the Ti coatings exhibited a high degree of porosity. Several methods were exploited in order to make the Ti coatings denser, including the incorporation of heavy, hard particles for in-situ peening during the coating deposition, and post deposition laser heating. Abstract only; no full-text paper available.