Effect of Annealing Atmosphere on the Recrystallized Texture and Abnormal Grain Growth of Ni–5%W Alloy Sheets

The effect of the annealing atmosphere on the recrystallization of Ni–5%W alloy used as substrate sheet for superconductor wire was investigated. The annealing was made in two different annealing atmospheres: hydrogen and argon. After analyzing the recrystallized texture and microstructure by EBSD, the main texture component formed in both annealing atmospheres is the {100}<001> cube orientation. Furthermore, it is shown that hydrogen promotes the cube texture development, while argon slows down its development. Besides, it is shown that hydrogen favors the triggering of the abnormal grain growth at a temperature higher than 1 120 °C, while under argon, the abnormal grain growth is not observed before 1 200 °C. Then, an optimized annealing process has been put forward combining both the atmospheres. Note that the origin of hydrogen and argon effects on boundary mobility is also discussed.