The vacuum infusion process can be used to fabricate fiber metal laminates with reduced manufacturing time and cost. In this method, the holes in the aluminum layers are created due to the better flow of the resin and to ensure that the fibers are completely impregnated. Created holes can cause problems in using these fiber metal laminates. For example, structural strength is reduced and some parts of the composite layers are exposed to environmental conditions. A proper solution to these problems has been proposed and investigated in this article. If a non-perforated aluminum layer is used as the first layer to be in contact with the mold, this layer becomes the outer layer of the structure made of fiber metal laminates. This non-symmetric fiber metal laminate will still be resistant to moisture and other environmental conditions due to the presence of an intact aluminum layer on the outermost layer, such as conventional fiber metal laminates. This aluminum layer also increases the strength of fiber metal laminates in comparison with fiber metal laminates that its all aluminum layers are perforated. In this paper, the effect of holes diameter of aluminum layers on the resin flow rate (consequently the duration of the fabrication) and the mechanical strength of the structure were investigated. The results showed that holes in the upper and middle layers of aluminum can significantly increase the speed of fabrication, but the presence of the holes causes a slight decrease in the final strength of the sample.
The scope of acoustic impedance matching of hybrid fiber metal laminates for shielding applications