Thermally Enhanced Kinetic Sprayed Titanium Coating: Microstructure and Property Improvement for Potential Applications

The titanium coatings fabricated by kinetic spraying using nitrogen process gas shows relatively poor bonding state, and resultant high porosity. In this study, through thermally associated process optimization, the deposition characteristics and properties of kinetic sprayed titanium coating were improved in nitrogen process gas condition with novel powder preheating setup. Especially, porosity of the coating dramatically reduced to around 1% due to thermal softening of the powder. Based on finite-element modeling (using ABAQUS/EXPLICIT 6.7-2), a prototype of particle deposition model was proposed, and the simulation results elucidated the experimental results reasonably with respect to interfacial thermomechanical responses which are correlated with adhesion factors. Formation of thermal boost-up zone (TBZ) at impacting interface accelerated by thermal energy as well as subsequent impact of particles explains well thermally associated bonding mechanism in kinetic spraying.