The effect of shot peening on the surface integrity and fatigue properties of aluminum-clad 7B04–T7451 aluminum alloy was studied

and the effect of the aluminum-clad layer on the shot peening effect was clarified. Vickers hardness tester

in-situ nanometer testing system

laser confocal microscope

X-ray diffractometer were used to analyze the changes of microhardness

surface profile

surface roughness and residual stress of the samples after shot peening. The fatigue life of shot peening specimens was tested by fatigue testing machine and the characteristics of fatigue fracture were analyzed by scanning electron microscope. The results show that the hardness of the surface layer of the shot peened aluminum-clad 7B04–T7451 sample increases gradually from the surface to the interior until the hardness of the base material

and the surface hardness is slightly higher than that of the original sample; The larger the size

the larger the surface roughness is; The residual compressive stress layer with a depth of about 150 μm is introduced by shot peening

but its residual compressive stress value and stress peak value are both small. The fatigue properties of the shot peening clad 7B04–T7451 aluminum alloy did not improve. Due to the significant increase in surface roughness and plastic deformation

the fatigue crack source was initiated faster on the surface of the aluminum-clad layer

and the fatigue life decreased.