Shockwave Induced Spraying: A New Cost-Effective Solid-State Spraying Process

Shockwave Induced Spraying (SISP) is a new solid-state spraying process for deposition of metals, alloys, cermets and polymers on virtually any type of substrate at lower temperatures than used in traditional thermal spray processes and with high deposition efficiencies and rates.  In thermal spray processes such as High Velocity Oxy-Fuel (HVOF) and plasma spraying, bonding is obtained by the combination of thermal and kinetic energy of the sprayed particles.  In such thermal spray processes, the thermal energy input, which typically involves melting of the feedstock material, is sufficient to produce undesirable oxidation, porosity, metallurgical transformations and residual stresses.  Similar to Cold Gas Dynamic Spraying (or Cold Spray), SISP can produce thick coatings onto a diversity of surfaces at reduced temperature, minimizing thermal effects such as oxidation, tensile residual stresses, and metallurgical transformations.  This innovative process can be used to enhance surfaces for corrosion protection, thermal insulation, thermal dissipation, wear resistance, electrical conductivity, restoration, and other applications without the detrimental effects of elevated process temperatures. In this paper, we review the working principles as well as potential benefits of the novel SISP technology for a number of applications.