Abstract
In order to investigate the tendency to interfacial fracture of adhesion systems in high humidity, three types of experiments were carried out for the adhesion systems which were composed of stainless steel (SUS304) and epoxy resin: the tests in which the water uptake was measured on the adhesion systems, the single-lap shear tests and the observations using fluorescent microscope on the metal/resin interphase. Bisphenol A type epoxy resin was chosen as a resin and ATU amine or DDM (p.p'-methylene dianiline) was used as a hardener. Firstly, stainless steel plates were coated with the epoxy resin, were immersed into water and were measured the time evolution of the water accumulation. From the tests, water uptake of the specimens made from epoxy resin hardened with DDM and stainless steel was found to be greater than that of the epoxy resin bulk. The single-lap shear tests were also conducted to measure the water degradations of the adhesion systems. Finally, new method to visualize the water diffusion and distribution on the interphase was proposed. We used rhodamine B as a tracer. Epoxy resin coated metals were immersed into the solution of rhodamine B. After the immersion, cut profiles of the specimens were observed using fluorescence microscope. Peak intensity was observed on the interphase between the stainless steel and the epoxy resin hardened with DDM.
