Abstract:In this work, multilayered niobium/zirconium (Nb/Zr) composites with different initial Zr thicknesses were processed by accumulative roll bonding (ARB). Microstructure, texture and mechanical property of the composites at different ARB cycles were systematically investigated. The results showed that the heterophase interfaces were well bonded and no intermetallic compounds formed. With increasing ARB cycles, shear bands formed cutting through the multiple metal layers. Necking and fracture of the Zr layers occurred preferentially in the composites with an initial Zr thickness of 1 mm. Dislocation cell structures were predominated in Nb layers, while a mixture consisting of grains with dense dislocations and dynamically recovered grains with a low dislocation density were predominant in Zr layers. In addition, texture evolution in Nb layers changed with varied initial thickness of Zr. When the initial Zr thickness was 1 mm, strong Cube orientation appeared in Nb layers. However, when the initial Zr thickness was 2 mm, rotated-Cube was the dominant texture in Nb layers with increasing ARB cycles. The textures in Zr layers were similar in the composites with different initial Zr thicknesses. After the first ARB cycle, the {10-13}<3032> orientation was the dominant texture. With increasing ARB cycles, this orientation was slightly weakened and minor {11-20} fiber texture developed. With the increase of the ARB cycles both yield strength and ultimate tensile strength increased monotonically for the composites with different initial Zr thicknesses. However, the maximum elongation firstly decreased and then increased with increasing ARB cycles. After the third ARB cycle, the maximum elongation reached 14.2% and 16.5% for the composites with the initial Zr thicknesses of 1 and 2 mm, respectively. The high strength and good plasticity of the composites originated from the significant grain refinement in the individual metals and the recovered Zr grains during ARB, together with the featured texture evolution in the Zr layers.