Mechanical and corrosion properties in 3.5% NaCl solution of cold sprayed Al-based coatings

The recent development of the cold spray method has made it possible to deposit dense coating with good adhesion and with almost no change in the microstructure, which is promising in repairing damaged Al-based aircraft skin. In this work, the in-situ shot-peening-assisted low-pressure cold spray method was used to deposit Al-based dense coatings with good mechanical and corrosion protection properties on AA 2024-T3 alloy. The detailed microstructure, coating adhesion, and corrosion protection performance were systematically investigated. A dense microstructure with low porosity (<1.7%), high cohesive strength (>45 MPa) is achieved for the coatings. By comparison, Al 5083 coating exhibited the optimum mechanical properties. The Al and Al 5083 coatings reveal similar pitting resistance and repassivation ability. During long-term immersion test (>480 h) the corrosion resistance of Al 5083 coating surpassed that of CP Al coating. In conclusion, Al 5083 coating has a good combination of mechanical and anti-corrosion properties.