Development of Application Technique of Aluminum Sandwich Sheets for Automotive Hood

Objective of this study was to develop basic techniques in order to apply aluminum sandwich sheets for an automotive hood part. The aluminum sandwich sheet is the material fabricated by adhering two aluminum skins to one polypropylene core. When it has the same bending stiffness as a steel sheet, it is 65% lighter than the steel sheet and 30% lighter than an aluminum alloy sheet. Therefore, it is notified exclusively as good substitutive materials for a steel body to improve the fuel efficiency. Through aluminum sandwich sheet, however, it has relatively lower formability than that of the steel sheet for automotive application. In this study, we fabricated a prototype of the automotive hood panel to develop application techniques of the aluminum sandwich sheet. For this purpose, various formability evaluations were carried out in order to secure the fundamental data for the measurement of sheet metal forming and the establishment of optimum application conditions of the sandwich sheet. From the results of these formability evaluation, it was found that the sandwich sheet could reduce the weight and maintain the flexural rigidity simultaneously comparing to the steel sheet. Through the formability tests, we have designed the hood part on automotive panels and fabricated a mould and the prototype