A356/2024 bimetal composites were prepared by pouring liquid A356 alloy on solid 2024 Al alloy substrate under liquid-solid rolling cast process.The effects of Zn intermediate layer and pouring temperature on microstructure and mechanical properties of A356/2024 bimetal composites were investigated

and interface shearing strength and hardness distribution of the composites were analyzed.The experimental results indicate that the aluminum alloy surface after Zn treatment can effectively remove the oxide film on the surface of the 2024 aluminum alloy substrate and form the Zn coating to avoid the re-oxidation.The shearing strength of the bimetal composites is improved by about 40%from 100 MPa to 141 MPa compared with that of ones by un-plating Zn bimetal composites when pouring temperature is 700℃

which is beneficial to utilize the Zn intermediate layer as a protective film and to improve the wettability during high pouring temperature.When pouring temperature is 700℃

due to the existence of the Zn intermediate layer

the hardness peak of the Zn pretreated composites will appear on the side of the 2024 aluminum alloy substrate compared with the Zn untreated composites

and the wider melting zone will be formed on the surface of 2024 alloy substrate and more hardened phase will be generated.