Behavior of adhesive joints in corrosive environment

Abstract

An experimental study was undertaken to determine the effect of corrosive environments on the strength of adhesive joints between pairs of glass-fiber-reinforced-plastic (GRP) plates and plates of GRP bonded to aluminum (Al). Two corrosive agents, each in three concentrations, were used: sulphuric acid (30, 50 and 60 percent) and sodium chloride (15, 20 and 25 percent). The results indicate a loss of strength with immersion time that levels off after a certain time. This loss of strength was more severe for the sulphuric acid than for sodium chloride. Ultrasonic attenuation of the adhesive joints was also monitored and it was found to increase with the immersion time, suggesting that the corrosion created inhomogenieties in the bond. The loss of strength and the increase in ultrasonic attenuation were both greater for greater concentrations of each of the corrosive agents. © 1987 Society for Experimental Mechanics, Inc.