Foamability and mechanical properties of in situ submicron MgAl2O4p/Al composite foams by ultrasonic method.

• Ultrasonic technique was used to fabricate composite foam. • A small volume of MgAl 2 O 4 can satisfy the foaming and stability. • MgAl 2 O 4 p/Al composite foams have good energy absorption capacity. Composite aluminum foams, which are reinforced with submicron MgAl 2 O 4 generated in situ using different weight percentages of SiO 2 precursor (0.3, 0.5, and 0.7 wt%), were fabricated by stir casting and ultrasonic treatment (UT). Experimental results indicated that the microstructural constitution of all the foams prepared was composed of α -Al, MgAl 2 O 4 and Fe based intermetallics. More uniform pore distribution and better stability were achieved in the foams corresponding to maximum SiO 2 addition. The mechanical properties of the MgAl 2 O 4 p/Al composite foams were investigated by the quasi-static compression test. The plateau stress and energy absorption are enhanced with increasing SiO 2 addition. These are mainly due to the presence of submicron particles in the microstructure. [ABSTRACT FROM AUTHOR]