Effect of metallic particle injection on emitted radiations in atmospheric plasma spray jet

For this study, a wide spectral band pyrometer system was used to detect in-flight particle state. The molten metal particles were produced by atmospheric plasma spray technology. The operation conditions such as hydrogen flow rate, injected powder, the distance from the exit of plasma torch nozzle and the particle feed rate have large influence on the temperature measurement of wavelength radiometry. It was found that the emitted radiations were proportional to the plasma energy which depend on the particle heating history and particle mass flow rate. Far from the torch nozzle, the plasma emitted radiations increased with the particles in the flow and it was proportional to particles mass flow rate.