Influence of Environmental Ageing and Displacement Rate on Crack Resistance of Adhesives, as Determined on Adhesive Bonded Tapered Double Cantilevered Beam Specimens

摘要

Fracture toughness measurements were carried out to test the aging behavior of three adhesives in different environments. Metlbond 328, EC 2216 and REDUX 775 were tested on precracked 16 mm aluminum alloy (2024) plates in air at 90% relative humidity at 293 K and 373 K up to 4 weeks. Chromic sulfuric acid etching followed by chromic or phosphoric acid anodizing were the surface treatments used. Constant displacement rate tests were carried out to determine crack growth resistance R. Constant crack opening displacement tests were made to determine crack extension and crack growth resistance. It was possible to compare and evaluate adhesives and surface pretreatments. Phosphoric acid anodizing resulted in different durabilities for the adhesives. For a rate sensitive adhesive high displacement rates resulted in large crack extensions and high cracking rates.