Effect of Cold Spraying Parameters and Their Interaction an Hydroxyapatite Deposition

Cold spraying has been effectively investigated for spraying of various metals, alloys and composites. Coating of bio-ceramics like Hydroxyapatite (HAP) using thermal spraying has been investigated extensively, but there is a dearth of research related with HAP deposition using cold spraying. The relative percentage contribution of five important cold spraying parameters, their optimum combination and expected HAP particle velocity at optimum combination have been extensively discussed by the author, but no researcher reported the interactional effect of cold spraying parameters on HAP particle velocity. This paper examined the severity index of interactional effect of five important factors of cold spraying viz. gas type, gas inlet pressure, gas inlet temperature, particle size and particle temperature on HAP particle velocity. Most influential factor pairs and their influence on HAP particle velocity have been discussed with respect to various cold spraying gases viz. air, hydrogen, nitrogen and helium. In addition, CFD gas pressure and temperature distributions along the nozzle length and their mathematical validation have also been undertaken in the present paper.

Keywords:

CFD , Cold spraying , Taguchi , Particle Velocity