Direct observation of annealing twin formation in a Pb-base alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 454; pp. 629 - 636
• Main Authors: Song, K.H., Chun, Y.B., Hwang, S.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 25.04.2007; Elsevier
• Subjects: Annealing twins; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities in crystals; microstructure; Electron back-scattered diffraction (EBSD); Exact sciences and technology; Grain and twin boundaries; Lead-base alloy; Materials science; Other heat and thermomechanical treatments; Physics; Random high-angle boundaries; Special boundaries; Structure of solids and liquids; crystallography; Treatment of materials and its effects on microstructure and properties; Lead-base alloy; Electron back-scattered diffraction (EBSD); Special boundaries; Annealing twins; Random high-angle boundaries; Lead base alloys; Crystal twin; Annealing; High angle grain boundary; EBSD; High angle boundary; Growth mechanism; Thermomechanical treatments; Microstructure
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2006.11.151

Behaviors of random high-angle grain boundaries of a Pb-base alloy during thermo-mechanical processing and heat treatment were studied with the electron back-scattered diffraction method. Repetitive thermo-mechanical processing was found to be effective in increasing the fraction of special boundaries, and this was attributed to the ∑3 boundaries associated with annealing twins. Evidence was found that the dissociation of fast moving random high-angle boundaries to ∑3 boundaries correlates with other random boundaries. Also formed during intermittent thermal exposure were ∑3 n networks, which evolved mainly into ∑3 boundaries of lower energy. The present work thus supports the ‘growth accident’ model of annealing twin formation. Viable thermo-mechanical treatments for promoting the special boundaries are also proposed.