Effect of the grain boundary on the evolution of deformation in a bicrystal

• Published in: Journal of materials science 2005-06, Vol.40 (12), p.3225-3229
• Main Authors: ZIEGLER, A, CAMPBELL, G. H, KUMAR, M, STÖLKEN, J. S
• Format: Article
• Language: English
• Subjects: Applied sciences; Bands; Bicrystals; Compression tests; Condensed matter: structure, mechanical and thermal properties; Crystal lattices; Crystal structure; Defects and impurities in crystals; microstructure; Deformation; Deformation and plasticity (including yield, ductility, and superplasticity); Deformation effects; Exact sciences and technology; Grain and twin boundaries; Grain boundaries; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Metals. Metallurgy; Physics; Plastic deformation; Rotation; Single crystals; Strain localization; Structure of solids and liquids; crystallography; Tantalum; Twist boundaries; Work hardening
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-005-2689-x

The role of grain boundary constraint in strain localization and concomitant constitutive response was examined by performing a series of uniaxial compression tests on a tantalum bicrystal. Tantalum single crystals were diffusion bonded to form a (011) 90^∘ twist boundary that was compressed along the common [011] direction. The plastic deformation resulted in the creation of deformation bands away from the highly constraining grain boundary, resembling those bands known from single crystal plastic deformation. Near the grain boundary, such deformation band formation could not be detected. Instead a distinctive pattern of crystal lattice rotation was observed that filled a rather large volume (several millimeters in size) around the bicrystal grain boundary. The internal deformation band structure as well as the crystal lattice rotation pattern near the bicrystal grain boundary were characterized and found to give greater rates of work hardening in the neighborhood of the grain boundary.