Thermal gradient of in-flight polymer particles during cold spraying

Chrystelle A Bernard (1, 2) , H. Takana (3) , G. Diguet (2) , Kesavan Ravi (2, 4) , O. Lame (5) , Kazuhiro Ogawa (2, 4) , J.-Y. Cavaillé (2)

1 FRIS - FRIS - Frontier Research Institute for Interdisciplinary Sciences
2 ELyTMaX
3 IFS - Institute of Fluid Sciences [Sendai]
4 Tohoku University [Sendai]
5 MATEIS - Matériaux, ingénierie et science [Villeurbanne]

The manufacture of polymer coatings via the cold-spray process remains challenging owing to the viscoelastic-viscoplastic behavior exhibited by polymers. One crucial step to improve cold-spray polymer coating is to determine the particles' thermal history during their flight from inside the nozzle to their impact on the substrate. In this study, we propose estimating the velocity and temperature of an isolated polymer particle traveling through a nozzle with a sharp change in its cross-section. The preliminary results show that the geometric discontinuity constricts the flow, thereby increasing the particle velocity. Moreover, a significant thermal gradient is expected inside the particle, which in turn leads to a gradient of mechanical properties of the polymeric particle during impact.

Mots clés: Cold spray; Fluid dynamics; Polymer; Thermal gradient; Particle velocity

Domaines: Mécanique des fluides [physics.class-ph]; Génie des procédés; Thermique [physics.class-ph]

Chrystelle A Bernard, H. Takana, G. Diguet, Kesavan Ravi, O. Lame, et al.. Thermal gradient of in-flight polymer particles during cold spraying. Journal of Materials Processing Technology, 2020, 286, pp.116805. ⟨10.1016/j.jmatprotec.2020.116805⟩. ⟨hal-02971035⟩