Automobile crash components are intricate hollow profiles, can be foam filled for improved crashworthiness. Foam filling of a hollow profile can be done ex-situ or in-situ. In the ex-situ method the foam cannot have intimate contact with the profile. In contrast, the in-situ method involves foaming within the hollow profile, thus facilitates intimate contact between the foam and the profile leading to enhanced mechanical properties. The bonding between foam and profile increases effective load transfer during compression, enhancing mechanical properties. An attempt was made in obtaining good metallurgical bonding between foam and profile. Finally comparison of mechanical property was made between ex-situ and in-situ (with and without bonding) to understand the deformation behavior.
Copper electro plating was applied on the inner wall of the steel tubes for developing metallic bonding between foam and steel tube during foaming. Increasing copper coating thickness helped in reducing Fe-Al (Fe2Al5, FeAl3) intermetallics and promoted formation of CuAl2 and Al3Fe2Si compounds at foam and steel tube interface. In-situ foam filled steel tubes with good metallurgical bonding are superior in compression properties.