In this study, aluminum powder is cold sprayed onto copper, Al 5052, and 304 stainless steel substrates at working gas temperatures of 200, 300, and 400 °C. In-flight particle temperatures and velocities are determined theoretically and compared with experimentally measured values. It is shown that particle velocity increases with increasing gas temperature, while critical velocity falls. At 400 °C, a deposition efficiency of more than 95% was achieved. In contrast, the bonding strength at the coating-substrate interface is influenced much more by the substrate material than gas temperature.

The velocity of particles prior to the impact on the substrate surface is a very important factor that determines the deposition characteristics and coating quality in cold spray. The DPV-2000 system is an on-line diagnostic system that simultaneously measures the velocity, temperature and diameter of thermally sprayed particles. In the present study, the DPV-2000 system was employed to measure the velocity and diameter of cold sprayed particles. The effects of pre-setting software parameters of the DPV-2000 system on the measured particle velocities were investigated. The experimental results showed that the pre-setting values of the software parameters produced a significant influence on the accuracy of measured results.