This study compares the deposition behavior of kinetic sprayed bronze-diamond composite coatings produced using different mixtures of helium and nitrogen gas. To determine impact properties of the diamond particles, bare and nickel-coated diamonds are deposited on bronze layers and the effects of plastic deformation are examined using SEM and finite-element analysis. The results indicate that the deposition efficiency of diamond is determined by several factors and depends more on the angle and shape of the diamond particles than on the deformation properties of the bronze matrix.

In this study, Cu-based bulk metallic glass coatings were deposited by atmospheric plasma spraying with different hydrogen flow rates. The crystallization and oxidation of the coatings is assessed along with corrosion resistance. As thermal energy in the plasma jet increases, the melting fraction and oxidation of particles in the coating increases as does porosity. All of these factors have an effect on the corrosion resistance of Cu-based bulk metallic glass coatings and their relative impact is discussed.

In this work, effect of substrate roughness on the deposition behavior of the particles through kinetic spray technology is studied. Finite element analysis program, ABAQUS 6.7-2 was used to estimate the results. Particle impact on the planar and roughened substrates were analyzed and compared. Interface temperature, contact area and contact time were found to be higher for the particle impact on roughened surfaces than that of the planar one for constant spray condition. These factors are significant for bonding mechanism. Experiments were performed on the polished and grit blasted surfaces in order to compare the results. The deposition efficiency and the bond strength values were used to evaluate the effect of surface roughness.

In this study, individual particle impact behaviors of soft particle on hard substrate were observed. The ratio of bonds was compared to the difference between adhesion and rebound energies. To improve the existing model, the equation for effective yield strength was modified and finite element analysis was applied to estimate the temperature and strain gradients. The energy difference was derived from the strain and temperature of the elements and compared to the experimental ratio of bonds.

In this study, three kinds of engineering metals, which are aluminum (1100-H12), commercially pure titanium and mild steel were combined as particle/substrate and classified into four cases, i.e., soft/soft, hard/hard, hard/soft and soft/hard, according to their physical and mechanical properties respectively. Based on finite element modeling, impacting interface elements of four cases were analyzed and impact behaviors were numerically characterized. For soft/soft and hard/hard cases, the maximum temperature at the substrate side, which approached melting point, is higher than that of particle side when the shear instabilities occur. In particular, the different size of thermal boost-up zone was numerically estimated and theoretically discussed for these two cases. Meanwhile, for soft/hard and hard/soft cases, the specific aspect of shear instability, which has very high heat-up rate, was always observed at the relatively soft impact counterpart, and a thin molten layer was expected as well. Thus, the successful bonding of the above mentioned four cases can be predicted as a result of the synergistic effect of localized shear instability with interfacial melting.

Kinetic spraying process that is basically a solid-state deposition process was used for the formation of a fully amorphous coating. As the application of pre-heating system for the powder carrier gas and using Helium for the process gas, it was possible to form of amorphous coating. Main process parameters evaluated in this study were gas species[N 2 and He]and pre-heating temperature[RT(below Tg) and 550 (liquid metallic region)] for carrier gas. Aside from empirical approach, in-flight particle velocity within kinetic spraying process was measured with spray-watch- 2i. The deposition behaviors of a NiTiZrSiSn bulk amorphous powder were observed when it was sprayed using kinetic spraying process. When the bulk amorphous feedstock material was coated, both kinetic energy and thermal energy of the in-flight particle are important. The former did affect on the deposition of the bulk amorphous coating, while the later did more affect on mechanical properties of coating. Particle deposition behaviors were considered from the viewpoint of the environmental effect such as particle energy combination on the deposition behaviors. The bonding of the impacting NiTiZrSiSn bulk amorphous particle was primarily dependent on the temperature dependent deformation and fracture(local liquid drop formation) behavior.