The diagram illustrates the various trajectories that particle distributions may follow. Each trajectory shown represents extremes in particle heating, and this affects the average condition of the particles on impact (liquid, solid + liquid).
A fortunate law of nature is that the smaller-diameter particles do not have enough momentum to penetrate the hottest portion of the jet core. Therefore, smaller particles are not heated as long as the larger ones; larger particles, with their higher momentum, penetrate to the jet core.
High carrier gas flows (velocity) may force larger particles to follow a trajectory that passes through the jet to the opposite side of the plasma. This would result in decreased heating and possibly cause a buildup of powder on the nozzle bore.
Volume 5A, Thermal Spray Technology ⇒ Thermal Spray Processes and Coatings ⇒ Thermal Spray Processes ⇒ Thermal Spray Processes
