Study on interface behavior and mechanical properties of Al/Cu laminated tubes fabricated by strong staggered spinning at room temperature

Abstract

In this paper, Al/Cu laminated tubes were fabricated by strong staggered spinning at room temperature. The interface behavior and mechanical properties of the laminates with different thinning rates were studied. The results show that the laminated tubes have good deformation coordination, no obvious interface defects and good bonding. With the increase of thinning rate, the metals in the diffused layer decrease during the spinning process and transition to the new diffused layer interface, and the interface bonding strength is improved, the microstructure on both sides of the interface becomes finer and more uniform. The Cu side is dominated by fibrous texture and equiaaxial grains formed by recrystallization, forming strong shear Brass-R {111} <110> texture. The Al side grains are mainly equiaxed, forming deformed Goss {110} <001> texture. Due to the strong plastic strain exerted by the diffusion layer metal on the surrounding material and the occurrence of dynamic recrystallization (DRX), the average grain size on the Cu and Al sides near the interface decreased to 1.18 μm and 1.33 μm at a 70% thinning rate, respectively. With the increase of thinning rate, the yield strength (YS) and ultimate tensile strength (UTS) of laminated tube increase first and then decrease. Compared with the BM, YS (131.0 MPa) and UTS (180.9 MPa) of the sample with 50% thinning rate increase 50.4% and 64.0%. The increase in strength is attributed to work hardening and grain refinement. The fracture mechanism is brittle fracture on Cu side and ductile fracture on Al side.