In-situ TiB 2–Al 2O 3 formed composite coatings by atmospheric plasma spraying: Influence of process parameters and in-flight particle characteristics

Abstract

In the present study, mechanically alloyed Al–12Si, B 2O 3 and TiO 2 powder was deposited onto an aluminum substrate using atmospheric plasma spraying (APS). The effects of mechanical alloying (MA) time and plasma parameters (arc current and primary/secondary/carrier gas flow rate) on in-situ reaction intensity and in-flight particle characteristics (temperature and velocity) have been investigated. It has been observed that MA time has a remarkable effect on powder morphology and relative amount of in-situ formed TiB 2 and γ-Al 2O 3. In-flight particle diagnostic measurements demonstrate that among the plasma parameters arc current has the strongest effect on in-flight particle velocity and temperature. Also, results indicate that in-flight particle velocity is more dominant than temperature on the relative amount of in-situ formed phases.