Abstract
In this paper, the authors evaluate a pulsed plasma spraying process for producing ceramic coatings. Experiments were conducted with a specially developed torch with a discharge current of 24 kA and a pulse duration of 400 μs. The in-flight characteristics of alumina particles injected into the pulsed plasma stream were measured and analyzed. The surface temperature of alumina particles reached 2,700 to 3,300 K, which is well above the melting point. Particle velocity was found to be around 200 m/s, which is comparable to particle velocity in dc plasma streams. Coatings formed with one shot of pulsed plasma were examined using scanning electron microscopy, and the results confirm the applicability of pulsed plasma to the spraying of refractory materials.