Published online by Cambridge University Press: 26 February 2011
Copper wires annealed at 1000°C to produce a ‘bamboo’ grain structure were used to measure the grain boundary energy, γB, and its dependence on boundary plane orientation, δγB/δϕ. Data for boundaries between crystals showing the ∑11 orientation relation were used to integrate the δγB/δϕ values to give a ‘γB-plot’ for ‑11 boundaries. The ‑11 and ‑33 γB-plots were added together. Comparison with a ‑33 YB-plots indicates the conditions under which a ‑33 boundary dissociates into separate ‑11 and ‑33 boundaries.