Observations on the effect of a magnetic field on the annealing texture and microstructure evolution in zirconium

The effect of a magnetic field on the development of texture and microstructure in cold-rolled (80%) commercially pure zirconium (Zr701) was investigated. The specifically oriented sheet specimens were annealed at 550°C for 15, 30 and 45min and at 700°C for 60, 90 and 180min in a magnetic field of 19T and 17T, respectively. X-ray diffraction and electron backscatter diffraction measurements were used to characterize the crystallographic texture and the grain microstructure. The results revealed that the magnetic annealing promotes grain growth in the investigated material. This becomes apparent from the faster development of specific “grain growth” texture components and the bigger mean grain size after magnetic annealing. Magnetic annealing at 700°C resulted in asymmetry of the two major texture components that constantly increased with annealing time. This effect is attributed to a magnetic driving force for grain growth arising from the anisotropic magnetic susceptibility of zirconium.