High Rate Deposition in Cold Spray

Industrialization of cold spray introduces concerns regarding the cost and time efficiency of cold spray procedures. In this work, high rate deposition of tantalum was studied computationally and experimentally. Quasi-1D multiphase fluid simulations predicted minimal effects on the bonding conditions of particles with 5% to 14% increase in powder-to-gas mass flow ratio. Experimental specimens were produced to observe the mechanical and microstructural effects of increased powder stream loading. Adhesion and hardness tests as well as thermal conductivity, optical microscopy, and electron backscatter diffraction examinations only exhibited minor differences in the mechanical and microstructural properties of the specimens. The increased powder stream loading rate, however, allows a significant reduction in the time required for depositing the same amount of tantalum by a factor of three. The results of the study enable shorter cold spray deposition time. This leads to significant cost savings associated with consumption of helium and labor, while facilitating shorter turn-around times for repairing components and manufacturing of cold-sprayed products.