The influence of grain boundary geometry on intergranular crack propagation in Ni[sub 3]Al
- Univ. of Pennsylvania, Philadelphia (United States). Dept. of Materials and Engineering
The distribution of grain boundary types along intergranular cracks in Ni[sub 3]Al was measured, by [Sigma] value, and compared to the distribution in the bulk, using statistically significant sample sizes. It was found that low angle ([Sigma] 1) and symmetrical [Sigma]3 boundaries (twins) are particularly strong, and all high angle boundaries, independent of their [Sigma] values are weak. In particular, low [Sigma], high angle boundaries, as a group, are also weak. These results are in qualitative agreement with predictions based on the structural unit model and imply that the fracture strength of an intergranularly brittle polycrystalline aggregate can be increased only by increasing the fraction of low angle and symmetrical [Sigma]3 boundaries.
- OSTI ID:
- 6302729
- Journal Information:
- Acta Metallurgica et Materialia; (United States), Vol. 41:2; ISSN 0956-7151
- Country of Publication:
- United States
- Language:
- English
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