Abstract
In order to improve fuel consumption and collision safety of a car, application of ultra-light porous metals having high specific rigidity and good impact energy absorption to various car parts are hopeful. Generally, it is thought that the applicable porous metals include closed cells and their relative density is less than 0.3. Especially, metallic hollow sphere (MHS) structure is comparatively homogeneous and has high reliability to apply it to the car parts. However, production cost, insufficient controllability of performance and weak tensile strength have been problems yet. To solve these problems, we propose a ball-chain type MHS structure. Many strings of metallic hollow spheres are precisely produced from thin metal sheets by plastic working with dies and then the strings are consolidated. Since the neighboring hollow spheres are connected by a bridge, the tensile strength may be improved. In this paper, the fabrication method and results of simple compression, simple tension and 3-point bending tests of the structure are reported.
