Comparison of the Effects of Shot Blasting and Sandblasting Processes on the Strength of the Aluminum Adhesive Bonded Joints

In this paper, the influences of surface roughness on the strength of the single lap adhesive joints for the prepared adherent with shot blasting and sandblasting processes were examined. Sheets from 2024-T3 aluminum alloy were cut into pieces and then shot blasted at four different durations and sandblasted with four different pressures. Prepared aluminum specimens were jointed using two different adhesives, two-component Araldite 2015 with high viscosity and epoxy HPL1012/HPH112 with low viscosity. The effects of process parameters on the surface roughness of the adherent and ultimate shear strength of the joint were investigated using design of experiments technique. Tensile test was used to determine the ultimate strength of the joints. The obtained results were presented comparatively. It was shown that by increasing the surface roughness of shot blasted and sandblasted samples, the ultimate shear strength of the joints increases continuously. The optimum surface treatment for ductile and brittle adhesives was similar that shown no relation of this optimum roughness to adhesive type in the prepared samples with sandblast and shut blast processes. The highest ultimate shear strength was obtained for the sandblasted specimens at maximum pressure of 6 bar with 0.6 micrometers of surface roughness.