The associated effect of powder carrier gas and powder characteristics on the optimal design of the cold spray nozzle

Abstract

During cold spray, the temperature of the particle carrier gas is at room temperature, which is lower than the preheated propulsive gas and affects the mixed gas temperature and particle acceleration. This study is investigating the associated effect of the powder carrier gas and powder characteristics on the optimal design of the nozzle using numerical simulations. The results show that the heat exchange of mixed gas stabilizes, and temperatures of mixed gas and particles are higher in the nozzle when a larger inlet diameter and a longer convergent section are used. In addition, particle impact velocity is inversely related to its size and density. Therefore, heavier particles require longer divergent lengths and larger expansion ratios for a longer acceleration distance and increased kinetic energy. The nozzle geometry can be designed depending on the selected particles and the chosen propulsive gas, for a maximum particle impact velocity.

Cold Spray Additive Manufacturing of Ti6Al4V: Special Nozzle Design Using Numerical Simulation and Experimental Validation

“…increased particle diameter, steeper temperature rise in the convergent section, and drastic drop in the divergent sections can be observed (Figure 8a). The 5 μm particle yields the In our previous studies [35,50], we showed that particle size affects particle acceleration. The calculated particle temperatures of different-sized particles upon impact on the substrate are shown in Figure 7.…”

“…Particles at high temperatures are more likely to become soft and plastically deform during CSAM. In our previous studies [35,50], we showed that particle size affects particle acceleration. The calculated particle temperatures of different-sized particles upon impact on the substrate are shown in Figure 7.…”

“…This may indicate that the relationship between particle temperature and particle diameter first increases and then decreases. In our previous studies [35,50], we showed that particle size affects particle accelera tion. The calculated particle temperatures of different-sized particles upon impact on th substrate are shown in Figure 7.…”

“…The majority of published works have not studied the effect of the powder carrier gas with numerical modeling. It is known that the introduction of powder carrier gas at room temperature adversely affects the acceleration and temperature of particles [50]. Therefore, the powder carrier gas was also investigated in this study.…”

Influence of processing conditions on the mechanical, tribological and fatigue performance of cold spray coating: a review

“…During this spraying process, the ceramic particles are accelerated by supersonic velocity using carrier gas through a nozzle towards the substrate at room temperature in a vacuum chamber [21]. This process has high deposition efficiency and is used for coating electronic appliances [22,23].…”