Cold rolling evolution in high purity niobium using a tapered wedge specimen

A tapered wedge niobium specimen was rolled at room temperature with multiple passes in the same direction without lubricant and then annealed at 750 °C for 1 h. The crystal orientation distribution of the 50%, 70%, 80%, 90% deformed samples was investigated using X-rays to obtain a quantitative texture analysis. The initial rotated cube {0 0 1}〈1 1 0〉 texture was largely retained up to about 70% reduction in the interior of the samples. After 80% rolling deformation the initial texture vanished and revealed a {1 1 1} fiber texture in the interior, which remained stable during annealing. With 90% reduction, the {1 1 1} fiber texture become somewhat stronger. In the surface layer, the 0 0 1 fiber orientation remained stable but after annealing, the surface texture sharpened to become {0 0 1}〈1 1 0〉.