Investigating the effect of the shot peening process on the properties and quality of Al-Al2O3 composite coating created by cold spraying

In this research, Al-Al2O3 composite coating was created using cold spraying process on Al-1050 alloy sheet. In order to create the coating, pure aluminum powder and Al2O3 powder were mixed with equal weight percentage (50% wt.). The coating was done using nitrogen gas at a temperature of 300 ℃ and a pressure of 30 bar and a spraying distance of 20 mm. Moreover, the coating was shot peened using a centrifugal process with a speed of 3000 rpm and peen size of 0.6 mm for 3 minutes. The effect of the shot peening process on the properties and quality of the coating was investigated. The characteristics of the coating were investigated using microhardness measurement, scanning electron microscope, Clemex image analysis software, and atomic force microscope. The results show that the hardness of the coating increases by 10% due to the shot peening process on the composite coating and the porosity of the coating decreases by 80% due to the shot peening process. The results of the atomic force microscope show that the surface roughness increases due to the shot peening process, and on the other hand, the coating thickness decreases due to condensation and wear.