Injection Observations on Suspension Plasma Spray Utilizing Laser Based Visualization Techniques

Laser Based Particle Visualization instruments such as SprayCam provide a unique picture into the radial injection of powders in Atmospheric Plasma Spray (APS) processes.  SprayCam uses an extremely short (35ns) pulsed diode laser in a back illumination configuration to create high quality images of micron-sized, high-velocity particulates or droplets within high temperature plasmas.  When these instruments are employed to study the injection of liquid feedstock in APS processes many useful insights can be gained regarding injection penetration and droplet atomization.  An examination of the atomization and penetration of the liquid feedstock is conducted on both Suspension Plasma Spray and Solution Precursor Plasma Spray under a variety of liquid injection velocity and torch speed conditions.