Mechanism of grain growth during severe plastic deformation of a nanocrystalline Ni-Fe alloy

作者：Wang Y B^*; Ho J C; Liao X Z; Li H Q; Ringer S P; Zhu Y T

来源：Applied Physics Letters, 2009, 94(1): 011908.

DOI：10.1063/1.3065025

• dislocations
• grain boundaries
• grain growth
• iron alloys
• nanostructured materials
• nickel alloys
• plastic deformation
• transmission electron microscopy

Deformation induced grain growth has been widely reported in nanocrystalline materials. However, the grain growth mechanism remains an open question. This study applies high-pressure torsion to severely deform bulk nanocrystalline Ni-20 wt % Fe disks and uses transmission electron microscopy to characterize the grain growth process. Our results provide solid evidence suggesting that high pressure torsion induced grain growth is achieved primarily via grain rotation for grains much smaller than 100 nm. Dislocations are mainly seen at small-angle subgrain boundaries during the grain growth process but are seen everywhere in grains after the grains have grown large.

• 出版日期2009-1-5