Abstract
The particle velocity in cold gas dynamic spraying (CGDS)
is one of the most important factors that can determine the
properties of the bonding to the substrate. The acceleration of
gas to particles is strongly dependent on the densities of
particles and the particle size. In this paper, the acceleration
process of micro-scale and nano-scale copper (Cu) and platinum
(Pt) particles in De-Laval-Type nozzle is investigated. A
numerical simulation is performed for the gas-particle two phase
flow with particle diameter ranging from 100nm to 50µm, which
are accelerated by carrier gas Nitrogen in a supersonic DeLaval-type
nozzle. The results show that cone-shape weak
shocks (compression waves) occur at the exit of divergent
section and the particle density has significant effect on the
accele ration of micro-scale particles. At same inlet condition, the
velocity of the smaller particles is larger than the larger particles
at the exit of the divergent section of the nozzle.