The aluminum/low carbon steel clad plate were fabricated by liquid-solid twin-roll casting

after annealing at 450 ℃ for 1.5 h and rolled for three passes. After each pass rolling treatment

the reduction rate of the clad plates reaches 25%

35% and 45%

respectively. The microstructure was observed and the element distribution of the interface was analyzed by SEM and EDS. The failure process of the clad plates was observed by in-situ tension

and the tensile strength and elongation were tested. The results indicate that there exists a continuous diffusion layer at the interface of the annealed clad plates

and the diffusion layer is broken into blocks under the pressure of the twin roll. Moreover

the greater the reduction rate is

the thinner the diffusion layer is

and the smaller the blocks is. Obvious gaps and holes are observed at the interface with the reduction rate of 25% and 35%

which disappear when reduction rate reaches 45%. The main cracks on the A356 side of annealed clad plates are originated from eutectic silicon particles and segregated eutectic silicon particles

and that of clad plates with reduction rate of 45% are formed by the rapid propagation of small cracks in the aluminum matrix. The clad plates with reduction rate of 45% exhibit the optimal bonding strength of interface and desirable ability of coordinated deformation

where the tensile strength reaches 441 MPa

and the elongation is 3.03%.