Relationship between surface roughness and load capacity of adhesive joints made of aluminum alloy 2024-T3 after shot peening

The aim of the work was to investigate the influence of selected shot peening parameters on the load capacity of adhesive joints and on the surface roughness of samples made of aluminum alloy 2024-T3. The research was also aimed at verifying whether it is possible to assess the load capacity of adhesive joints on the basis of the surface roughness parameters after shot peening. The treatment variants were developed according to the matrix of the Hartley's PS/DS-P:Ha3 plan. Shot peening time varied from 60 to 180 s, ball diameter from 0.5 to 1.5 mm and compressed air pressure from 0.3 to 0.5 MPa. As a result of the analysis of the correlation between the load capacity of connections and the surface roughness, it can be concluded that the greatest relationship exists between the load capacity and the Rku parameter. The regression analysis shows that the load capacity of the connections should increase along with the increase of the Rku parameter. The study also showed that the Rku parameter is also most strongly associated with the deflection of the Almen strips. The Almen strip deflection increases with the increase of the Rku parameter. The regression equation describing the influence of shot peening parameters on the value of the Rku parameter indicates that the value of the Rku parameter increases with the increase of the treatment time and the decrease of the ball diameter and the compressed air pressure.