Drop weight impact behavior of functionally graded aluminum foam consisting of A1050 and A6061 aluminum alloys

A1050/A6061 functionally graded aluminum foams (FG Al foams) with two layers consisting of A1050 and A6061 Al foams were successfully fabricated by the friction stir welding (FSW) route precursor foaming method. Drop weight impact tests of the FG Al foams were conducted to reveal the dynamic responses of the A1050/A6061 FG Al foams. The deformation of the FG Al foams started from the A1050 Al foam layer then spread to the A6061 Al foam layer during the impact tests regardless of the location of the A1050 Al foam layer in the specimens. The stress–strain curves obtained during the impact tests revealed two plateau regions with low and high strength corresponding to the deformation of each layer. The plateau stresses during the deformation of each layer were almost the same as those of uniform A1050 and A6061 Al foams. Consequently, it was shown that, by varying the base materials, it is possible to control the compression deformation behavior of FG Al foam with the desired plateau stress during impact tests, which depends on the strength of the base materials.