The deformation behavior and mechanical properties of a Cu 54 Zr 22 Ti 18 Ni 6 bulk metallic glass during and after deposition by kinetic spraying were investigated. The bulk metallic glass feedstock particles were manufactured by inert gas atomization and were subsequently deposited onto mild steel substrates by means of kinetic spraying at different powder carrier gas temperatures [room temperature, 450°C (within the supercooled liquid region), and 550°C (above crystallization temperature)]. In addition, the phase compositions of the feedstock and as-sprayed BMG coatings were investigated using X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), and Transmitted Electron Microscopy (TEM). With an increase of the powder feed temperature, it was deduced that more intimate contact of the particles with the substrate was achieved which decreased the porosity of the resulting coating. However, crystallizations, which seemed to be induced by severe deformation and accumulated heat, were observed at localized regions in the coating. In addition, micro-hardness and bond strength were affected by the crystallization degree of the as-sprayed coatings

This study evaluated the effects of particle temperature on deposition efficiency and critical velocity in kinetic spraying. A wide range of pressures and preheat temperatures of the process gas were used in these experiments to vary both particle velocity and temperature, and a bronze (Cu-Sn alloy) powder was deposited onto aluminum and bronze substrates. The deposition efficiency of the coatings was measured, and the critical velocity was estimated. The experimental results showed that the critical velocities of the bronze feedstock deposited onto either an aluminum or bronze substrate were different and that the critical velocity was strongly dependent on the particle temperature, which when increased, caused the critical velocity to decrease. Increasing the gas pressure caused an increase in particle velocity, while increases in the gas temperature not only affected the particle velocity but also the particle temperature. In our experiments, the critical velocity decreased by 50 m/s when the process gas temperature increased by 100 °C.