Using the 3-point bending method to study failure initiation in epoxide-aluminum joints

摘要: The increasing use of adhesives in industry has boosted the search for tests which allow adherence level to be defined. These tests, depending on type load, examine different stresses, failure modes and mixed modes. Furthermore, these can focused either initiation or propagation adhesive failure. subject this study is determined with 3-point bending test. Trials were conducted an aluminum 2024 substrate, two thicknesses, order understand impact adherend thickness. substrate received types surface pre-treatment: acetone cleaning, hydrochloric acid etching aminopropyltriethoxysilane coating. Two used: first one was a mixture epoxy pre-polymer DGEBA DETA amine, whereas second commercially formulated adhesive, ELECOLIT 6604. obtained by test verified SEM analysis. loads measured enabled effect treatment revealed: results indicate that silane most efficient comparison course simple degreasing. It assumed scatter each series due variation “intrinsic” between substrate. it noted thicknesses cannot compared thickness: therefore not possible simply compare same given substrate-adhesive system. energy approach proposed makes possible. requested initiate system then known, whatever initial geometry is. However, also shown thickness must correctly chosen. A thick increases dispersion thin may induce local unwelcome plastic strain. In conclusion, allows define criteria initiation.