Abstract
This paper describes improvement of the active laminate in bonding strength by using the oxide film of aluminum for insulation. Conventional types of the active laminates were made by hot pressing of an aluminum plate as high coefficient of thermal expansion (CTE) material, a unidirectional carbon fiber reinforced plastics (CFRP) prepreg as low CTE and electric resistance heater, and a unidirectional glass fiber reinforced plastics (GFRP) prepreg as low CTE and insulating material. However, the insulating layer reduces actuation capability of the active laminates and the bonding strength is insufficient. Therefore, a two-layer type active laminate was made by using anodized aluminum plate as high CTE and insulator material instead of using GFRP. In this study, the effects of thickness and pore diameter of the oxide film of aluminum plate on bonding strength between the aluminum plate and the CFRP layer of the two-layer type active laminate were investigated. The main results obtained are as follows: (1) Bonding strength and fracture energy between the aluminum plate and the CFRP layer of the active laminates can be improved by changing the type of oxide layer of aluminum plate from barrier oxide layer to porous one. (2) From chemical aspect, it is assumed that the improvement shown in bonding strength is caused by hydrogen bonding.
