Current methods used to characterize high strain rate particle impacts relevant to cold spray processes are limited in resolving deformation characteristics and observing viscoelastic behavior of particles during deposition. This leaves critical gaps in the understanding of particle-substrate interactions and adhesion mechanisms. The primary objective of this research is to provide insight into high strain rate deformation behavior and viscoelastic properties of particles in cold spray-like impacts for the purposes of material vetting and optimization of spray parameters for deposition quality and efficiency. Experimental methods involving ultra-high-speed video capture of macroparticle (~3mm) impact experiments have been adapted for the observation of micron-scale single particles. A light gas gun previously used for macro particle impact experiments was adapted to launch micron scale particles at controlled velocities and particle/substrate temperatures representative of cold spray conditions. Analytical techniques employed for understanding impact mechanics focused on characterization of deformation profiles, viscoelastic behavior, and presence of advantageous features. This research demonstrates the capabilities of a new in situ experimental approach in capturing real-time deformation characteristics and viscoelastic behaviors of particles during high strain-rate impacts that are not apparent through traditional stroboscopic imaging or post-impact analysis techniques. This approach provides insight into adhesion and deposition mechanisms for cold spray and expands characterization capabilities with favorable deformation profiles for improved adhesion of viscoelastic materials on various substrates. The presented approach also provides insight into understanding cold spray adhesion and deposition mechanisms by observing single particle deformations with control over spray conditions beyond alternative imaging and ex situ characterization methods.
2025-04-09 09:00:00
