The Principal Hugoniot of Kinetic and Plasma Sprayed Refractory Metallic Deposits up to 10 GPa*

Controlled Atmosphere Plasma Spray (CAPS) and Cold Spray (CS) are coating processes which produce

deposits with porous, stochastic microstructures containing many interfaces due to imperfect layering of

feedstock particles upon impact. The two processes create vastly different microstructures and densities

for the same materials. We conducted gas gun experiments to measure the principal Hugoniot of

tantalum, niobium, and Ta/Nb blended films fabricated by both techniques in the range of 1-10 GPa. The

reverse-ballistic configuration was used to impact kinetic and plasma sprayed samples into witness

windows with known shock Hugoniots (PMMA, LiF, and sapphire). A velocity interferometer (VISAR)

measured the particle velocity at the impactor-witness interface. Material responses were compared for

the low- and high- density deposits formed by CAPS and CS, respectively.