Low Pressure Gas Dynamic Spray: Shear Localization during Particle Shock Consolidation
Prof. Roman Gr. Maev and Evgeny Leshchinsky, Physics, University of Windsor, 401 Sunset Ave, Windsor, ON N9B 3P4, Canada

Gas Dynamic Spray (GDS) is a high rate, direct material-deposition process that utilizes the kinetic energy of particles sprayed at supersonic velocities to cause bonding through the particle plastic deformation on impact. GDS seems to be similar to the powder shock consolidation process, which is governed by dynamic regimes of granular material deformation under impulse loading. These regimes are characterized by adiabatic shear band (ASB) formation. This paper describes the preliminary analysis of ASB formation during GDS on the basis of a combination of the Johnson-Cook and shock wave consolidation models. The dependence of the ASB width on different parameters, including initial powder porosity, average impact stress, shear strain, initial temperature, and contact time was determined. The ASB width was found to vary in the range of 0.5 –15 μm, which reveals the great localization of particle deformation in the GDS process.

Cold Spray

The Preliminary Program for International Thermal Spray Conference And Exposition (ITSC) (May 15-18, 2006)