Abstract: Under different brazing time,pure aluminum foams were welded by contact reactive brazing in vacuum environment with multilayer filler metals.The macrostructure and microstructure characteristics and bending strength of the joints were investigated.The specimen,brazed at 570℃ for 15 min, failed through the base metal,while the others fractured through the brazed seam.The bending strength of joints firstly ascended to a peak point and then decreased with the increase of brazing time.The bending strength of joint brazed for 15 min reached the highest,stronger than that of the aluminum foam substrate.