Tailoring adhesive bonding strength: the role of mechanical abrasion and cure time in aluminum-stainless steel joints

Abstract Adhesive bonding is an efficient strategy for fabricating lightweight structural components owing to its superior toughness and fatigue resistance. Major factors affecting the adhesion of various materials encompass the elimination of impurities, adhesive wettability, and surface roughness. This study examines the effects of surface roughness and curing duration on the adhesive bonding of AL5083 and SS 304 substrates. Impurities are eliminated from the substrates utilizing laboratory-grade acetone, succeeded by pre-treatment with P30, P40, and P60 grades of silicon carbide sheets. Surface roughness is quantified using a profilometer Surftest (SJ-210). Morphologies were analyzed by scanning electron microscopy (SEM) and x-ray diffractometry (XRD) were employed to validate the specimen fabrication. The adhesively bonded specimens, exhibiting different surface roughness, undergo lap shear tensile tests utilizing a Universal Testing Machine (UTM), and tensile strength is determined. The results demonstrate that the surface treated with silicon carbide P30 and cured for 48 h attained the maximum tensile strength for both adherend materials: 129.00 MPa for SS 304 with a surface roughness of Ra = 3.20 μm, and 44.65 MPa for AL5083 with a surface roughness of Ra = 5.00 μm. This research will pave the way to optimize the surface preparation for bonded joints.