Seeking to realize weight savings in vehicle bodies, Honda has developed a lightweight and high cost-efficiency aluminum/steel-sheet hybrid door. Bimetallic corrosion in the area of connection between the two metals represented an issue for this door. The difference in electric potential between the two metals would promote corrosion, raising the possibility of a decline in commercial appeal. In order to address this issue, a sealer was employed to help prevent infiltration of water. In addition to providing watertightness in the use environment, it was necessary for this sealer to possess a low elastic modulus in order to help prevent distortion from being generated in the skin panel during the sealer curing process. A watertight structure was realized through the development of application specifications using a low-elasticity sealer.
Article of Honda R&D Technical Review Vol.25 No.1 (68 - 71)