Interface Characterization of the Mg/Al Laiminated Composite Fabricated by Accumulative Roll Bonding at Ambient Temperature

Mg and its alloy have large potential in weight reduction usages because of their low density. However, the relatively low strength and modulus hinder their widely applications. Accumulative roll bonding (ARB) is one kind of severe plastic deformation (SPD) process which can produce bulk ultra fine-grained (UFG) metallic materials. In order to improve the strength, elastic modulus and corrosion resistance of Mg sheet, accumulative roll bonding was utilized to fabricate UFG Mg/AI laminated composites at ambient temperature in this work. Synchrotron radiation-based computer tomography, SEM and TEM were employed to characterize the global bonding condition and the interface structure of Mg/AI lam-inated sheet ARBed after 3 cycles. No obvious cracks could be observed along the bonding interfaces during ARB, although small amount of tiny pores existed in some area. Mg17Al12 phase with thickness of 150 nm formed at Mg/AI interface after 3 cycles. There existed a definite orientation relationship between Mg17Al12,2 and Mg which is [111](mg17A112) (1210)(mg) , (110)(mg17Al12)//(1011)(mg.) Nevertheless, the orientation relationship between Mg17Al12,2 and Al is not very obvious.