Aiming at the high porosity open cell aluminum foam（sponge aluminum）prepared by investment casting method

the relative density of sponge aluminum is increased by increasing the thickness of the struct in the precursor

and the effects of struct size on the compression performance were investigated.The results reveal that the struct of polyurethane sponge can be thickened effectively by using waterborne polyurethane resin（WPU）

and the foam aluminum with pore edge thickness of 0.472～0.918 mm and relative density of 0.027～0.164 were prepared.The results of uniaxial compression test indicate that the strength of sponge aluminum is greatly enhanced by increasing the struct.When the thickness of struct is 0.918 mm

the densification platform and energy absorption reach the maximum

which are 2.831 MPa and 1.492 MJ/m

3

respectively.The reason is that the relative density is increased with the increase of struct thickness

improving the energy absorption capacity of sponge aluminum.