Study of Moisture Diffusion Behavior in Hybrid IM7/BMI Composites

摘要

Moisture diffusion behavior in IM7 carbon fiber-reinforced bismaleimide composites (IM7/BMI) is investigated under two different temperatures at 100% relative humidity. Three-ply uni-weave, four-harness satin weave and a hybrid of uni-weave and satin weave composites are utilized for the present study. Diffusion behaviors in these IM7/BMI composites are found to be significantly influenced by laminate architecture. A one-dimensional finite element model based on Fick's second law is used to predict the moisture diffusion behavior in hybrid composites. It is found that both the neat resin and composites follow the Fickian diffusion behavior only at short times. At longer times, moisture diffusion begins to deviate from Fickian behavior and suggests that additional moisture absorption mechanisms take place.