The characteristics of adhesive joints of aluminium sheet containing epoxy based composite adhesives containing nano-filler of ZrO2 powder have been studied. The composite adhesives containing 10, 15 and 20wt.% of about 20±3 nm size ZrO2 powder are applied to mechanically treated aluminium substrates. The single lap joints of the composite adhesive are characterized by their tensile lap shear strength as a function of the bond-line thickness as well as the amount of filler. The characteristics of the composite adhesive joint have been compared to those of the conventional epoxy adhesive joints. The bond-line thickness of the adhesive with respect to the amount of the ZrO2 nano-filler has been optimised for maximum tensile single lap shear strength of the adhesive joint of mechanically treated aluminium substrate. In comparison to conventional epoxy adhesive joints, the nano-filler epoxy based adhesive joint of aluminium shows significantly improved lap shear strength as a function of bond line thickness of adhesive and amount of filler in it. (P K Ghosh & S K Nukala)
