Effect of Mo addition on the crystal texture and deformation twin formation in Zr-based alloys

The effect of Mo on the crystal texture of Zr–Nb and Zr–Nb–Mo alloys was studied. Molybdenum addition reduced the average sizes of the equiaxed α grains and the packets considerably. In the Zr–Nb alloy specimens free of Mo, the intensity of the normal basal texture increased with the initial grain size, which was attributed to the enhanced probability of twinning in coarse grains. Molybdenum also reduced the intensity of the normal basal texture of the Zr alloys, indicating a possible change in the mode of deformation caused by Mo addition. Moreover, the texture shift of the Zr alloys from ND–TD to ND–RD during annealing heat treatment was accelerated by Mo addition. Weakening of the normal basal texture in the cold-worked Mo-containing alloy, therefore, was attributed to the microstructural refinement and the change in the deformation mode.