The Corrosion Behavior And Life Rediction Of Glassfiber Reinforced Epoxyresin Composites Under Marine Environment

The glass fiber reinforced resin matrix composites (GFRP) with its excellentproperties has been widely used in aerospace, military and other fields. In recent years,due to its corrosion resistance, it is also gradually applied in the marine field, such as adashboard, raft, propeller, and various types of ship hull. However, the research in thecorrosion of GFRP is not as deep and broad as metal materials and research data aboutprediction of corrosion life is relatively little. So it has important significance to studythe seawater corrosion properties of GFRP and do the life prediction of it.GFRP was prepared by glass fiber as reinforcement and epoxy vinyl ester resin asmatrix through hand lay-up molding technology. In order to analyze and summarize thecorrosion forms, process and mechanism of GFRP, samples were put in artificialseawater immersion test under the normal temperature, wet-dry cycle test and hightemperature wet-dry accelerated test to study rates of quality changes, strength retention,mechanical properties and morphology analysis, etc. On the basis of accumulating dataand corrosion of aging mechanism established the thermal life prediction and thecorrelation between normal temperature and accelerated test.The results indicated that, after seawater corrosion, the surface color, gloss andthickness of GFRP were obviously changed with the extension of time, and a part ofsamples have bumps, cracking and other phenomena. Through normal temperaturewater immersion test, mechanical properties testing results show that the moisturewould cause the loss of the mechanical behavior of GFRP. The tensile strength ofsamples has fallen by57.69%and the bending strength decreased by60.67%after oneyear seawater corrosion. The wetting-drying test shows that wetting-drying circulationcan accelerate the speed of moisture absorption by the calculation of diffusioncoefficient and moisture absorption, diffusion coefficient D increased with the watersolution concentration, it was different with normal water immersion test. The tensilestrength of samples has fallen by62.91%and the bending strength decreased by67.25%after the normal temperature wetting-drying test. The shorter cycle length of circulationwas, the more mechanical strength of GFRP decreased. High temperature acceleratedtest research showed that moisture absorption rate under high temperature was about2times of room temperature. After raised the temperature, GFRP corroded by seawater isdue to large molecules break in to micromolecule and made the weight down. And the mechanical property of GFRP was decreased with the temperature. Finally, based on theaging of corrosion mechanism and the classical theory of Arrhenius, established thermallife prediction equation of GFRP isln t9009.11/T20.34according to the resultsand set up the correlation between normal temperature and accelerated test is6601.334(11)t/teT1T212.