Deformation behaviour at macro- and nano-length scales: The development of orientation gradients

• Published in: Materials letters Vol. 99; pp. 81 - 85
• Main Authors: Gurao, N.P., Suwas, Satyam
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.05.2013
• Subjects: deformation; Deformation and fracture; EBSD; nanocrystals; nickel; rolling; Size effect; Texture; Deformation and fracture; Texture; EBSD; Size effect
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2013.02.074

The deformation behaviour of macrocrystalline and nanocrystalline nickel shows a striking similarity in terms of higher intragranular misorientation and a texture with dominant Brass component on rolling. This is in contrast to microcrystalline nickel, with lower intragranular misorientation and typical Copper type texture. This has been attributed to the free surfaces in macrocrystalline sample and grain boundaries in nanocrystalline sample. Experimental evidence of ‘Grain Boundary Affected Zone’ (GBAZ) showing multi-slip in contrast to limited slip in the grain interiors has been provided. The similarity in evolution of texture and intragranular misorientation is explained on the basis of reduced contribution from the GBAZ at the two extreme length scales. [Display omitted] ► Higher intragranular misorientation in oligocrystalline and nanocrystalline nickel on deformation. ► Higher Bs{110}〈112〉 component for oligo- and nanocrystalline sample while dominant Cu{112}〈111〉 component for microcrystalline sample deformed to high strain by rolling. ► This is due to free surfaces in the oligocrystal and grain boundaries in nanocrystalline sample. ► Experimental evidence of ‘Grain Boundary Affected Zone’ can explain the similarity in deformation behaviour at the extreme length scales.