The Effect of Torch Hardware on Particle Temperature and Particle Velocity Distributions in the Powder Flame Spray Process

Abstract

Powder flame spray is a flexible, straightforward process. Particulate feed stock is heated and accelerated using an oxy-fuel flame. Liquid feed stock droplets impact the substrate, deform, and solidify to form a coating. Like other spray processes, coating microstructure and properties are directly related to particle velocity and temperature at the time of impact. Many controllable process inputs affect particle temperature and particle velocity. Data, from a series of designed experiments, exploring these factors and quantifying their significance are reviewed. These data show that multiple process inputs, especially torch hardware, can significantly affect particle temperature and velocity distributions in the powder flame spray process.