论文信息 - On the distribution of Σ for grain boundaries in polycrystalline nickel prepared by strainannealing technique

On the distribution of Σ for grain boundaries in polycrystalline nickel prepared by strainannealing technique

Abstract The Σ value for a total of 222 boundaries was evaluated in recrystallized polycrystals of 270 grade nickel. The specimens were strained at room temperature and annealed at 0.9 Tm in order to obtain a large grain size. Of the 222 boundaries, 91 were related to Σ3, 20 to Σ9, 13 to Σ27 and 4 to Σ81. Of the remaining, 80 were random with Σ> 97, while the others were evenly distributed among other CSLs. The occurrence of Σ3 in our polycrystals is comparable to that found in bicrystals (this is a little remarkable since the grains were free to rotate in the bicrystals but were constrained in the polycrystals), but we find a much greater incidence of Σ9, Σ27 and Σ81 boundaries. The explanation given is that in polycrystals, Σ9 boundaries are created by the impingement of two Σ3 boundaries, etc.

Rishi Raj | R. Raj | L. C. Lim | L. Lim

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