AbstractProper substrate preparation is an indispensible step for achieving strong adhesive joints. One consequence of such surface treatment is the enhancement of degree of mechanical interlocking between polymers and substrates, which, according to the literature, seems to increase the strength of the joint. A novel method based on photolithography is developed to texture aluminum oxide surface by controlling the pit size and its spatial distribution. Surface profile, surface physical chemical properties of this sample, and the lap shear strength of epoxy adhesive joints are compared with those of the phosphoric acid anodized (PAA) sample. It is shown that the lap shear strength of the textured sample is superior to that of the PAA sample. Surface profile data and mathematical analysis suggest that the inferiority of the PAA sample is probably due to the trapped air in the large pit in the surface resisting the penetration of adhesives. It also concludes that the high surface area provided by the multitude small pits in PAA sample is far from being fully utilized. This study opens up a new avenue to rationally improve the strength of adhesive joint by controlling the surface profile, the surface chemical properties, and the pressure during bond formation.
展开▼
