Cold spray deposition of 316L stainless steel coatings on aluminium surface with following laser post-treatment

Microstructure and tribological performance of tungsten carbide reinforced stainless steel composite coatings by supersonic laser deposition

“…However, in contrast to soft materials like copper or aluminum, the cold sprayed hard material coatings such as stainless steel coatings usually have obvious porosity when using nitrogen as propellant gas [4][5][6][7]. High porosity level dramatically decreases the corrosion resistant and mechanical properties of the coatings.…”

Effect of Cold-Spray Conditions Using a Nitrogen Propellant Gas on AISI 316L Stainless Steel-Coating Microstructures

“…Finally, the standoff distance between the nozzle and the substrate also affected the AISI 316L coating microstructures; a standoff distance of 40 mm produced the densest microstructure.it is difficult to produce cold-sprayed austenitic stainless steel coatings using nitrogen propellant gas. Austenitic stainless steel exhibits work hardening and resists plastic deformation, but when the sprayed particles are stacked on the substrate, the sprayed particle velocity with nitrogen propellant gas is significantly lower than with helium propellant gas at the same gas temperature [4][5][6][7]. As a result, the stacked stainless steel particles on the substrate do not deform completely, resulting in many voids between the stacked particles.It has also been reported that cold-sprayed 316L stainless steel coatings using nitrogen propellant gas exhibited a porous microstructure as opposed to coatings using helium propellant gas, whereas the use of a heat treatment up to 800 • C enabled the same coating microstructures to be dense [8].…”

Effect of Laser Surface Treatment on the Corrosion Behavior of FeCrAl-Coated TZM Alloy

“…The interface between the as-sprayed coating and the substrate was mechanically bonded, while the interfacial bonding has been reported to become stronger metallurgically after the laser treatment [8]. Quite a few research results showed that laser treatments reduced the porosity and strengthened the coating adhesion in many coating/substrate systems [8][9][10][11][12][13]. Figure 3 shows the typical surface appearance of oxidized specimens prepared with and without the post-laser surface treatment.…”

“…It has been reported that relatively high porosity, as well as poor adhesion in various coating/substrate systems, could be modified by such post-treatments. The laser surface melting process could significantly enhance the adhesion of the metallic coating layer to a substrate and reduce microdefects in the coating [8][9][10][11][12][13].…”