High strain rate deformation microstructures of stainless steel 316L by cold spraying and explosive powder compaction

Cold spraying is a new coating technique in which dense, tightly bonded coatings form only due to the high kinetic energy of impinging particles of the spray powder. These particles are still in the solid state during impact. Explosive powder compaction is a technique where powder is consolidated by a shock wave. In the shock front the powder is deformed under high strain rates, which under suitable conditions results in high-strength bonding of the particles. Thus, the microstructural features obtained by both techniques should be similar. This study correlates the microstructure of cold-sprayed 316L austenitic steel coatings in comparison to the microstructure of 316L samples obtained by explosive compaction. The results provide insight into the prevailing local deformation mechanisms, as well as into the physical background of observed phase transformations.