Strain–anneal growth of Zr 701 large crystals

The present paper establishes the optimal conditions for grain growth in low alloyed Zr during strain–annealing. It is shown that it is possible to produce quite large crystals, whose maximum size (8–9 mm) is of the order of magnitude of the largest crystals normally produced in pure zirconium. Micro-tensile specimens could be produced containing a single grain in the effective gauge length. Strain-induced boundary migration is then proposed as the preferential growth mechanism, and a simple calculation allows one to conclude that both tilted {0001}〈1010〉 and {0001}〈1120〉 orientations have a growth advantage linked to a predicted minimum stored energy.