The Inter-Connections of ∑3 and ∑9 Boundaries and Their Evolution During Grain Growth in Grain Boundary Engineered High Purity Copper

Abstract

We report that the grain boundary inter-connections (GBIC) of ∑3 boundaries in grain boundary engineered pure copper are composed of {1 1 1}/{1 1 1} and non {1 1 1}/{1 1 1}. The length fraction of ∑3 boundaries and the content of {1 1 1}/{1 1 1} GBIC in ∑3 boundaries are both increased during grain growth. The {1 1 1}/{1 1 1} GBIC of ∑3 boundaries is located at the closest plane {0 0 1} of the ∑3 super lattice. The ∑9 boundaries are discovered to have {1 1 1}/{1 1 5} and {0 0 1}/{4 4 7} GBICs, the former is strengthened while the latter is weakened during grain growth even though the length fraction of ∑9 boundaries is declined somewhat. The {1 1 1}/{1 1 5} GBIC of ∑9 boundaries is located at the closest plane {0 1 1} of the ∑9 super lattice.

Keywords: pure copper, ∑3 boundary, ∑9 boundary, grain boundary inter-connection, grain growth