Strain effects on annealing behaviours of moderately deformed nanocrystalline nickel

Abstract

We report the annealing behaviours of nanocrystalline nickel as a function of plastic strain. A broad exothermic reaction due to primary and secondary recrystallisations appears in moderately deformed samples that are enhanced by plastic strain. Texture analysis shows that predeformation and recrystallisation play an important role in grain orientation. A certain difference in texture evolution exists in samples predeformed to different strains. Defects such as stacking faults and twinning should be considered to pin down the underlying mechanisms. The final grain orientation indicates that twinning plays an important role in grain growth due to orientation selection.

Keywords:

• Nanocrystalline materials
• Thermal analysis
• Texture
• Recrystallisation
• X-ray diffraction

The present work was supported by the National Natural Science Foundation of China (grant nos. 51071183 and 50890170) and the Fundamental Research Funds for the Central Universities (project no. CDJXS11132225). The authors would like to acknowledge discussions with Q. Wei from the University of North Carolina at Charlotte.