| A Cu-6Al-2Ni tricrystal was rolled to 20 % of thickness reduction. The lattice orientation was determined by means of the mutual angles of the slip traces produced by microhardness indentation, at one site of each crystal before rolling, and at two, after rolling, respectively at interior of the crystals and near grain boundary regions. All sites are near the triple point of the tricrystal. From this double determination of the crystals orientation after rolling, inhomogeneous lattice rotation of the crystals is observed. The experimental lattice orientation changes are compared with the prediction of the FC, RC models. Those of two crystals are in good agreement with the prediction, while those of the third crystal, which is smaller than the other two and surrounded by them, are in disagreement. From this disagreement, together with a slip line system observed in a microstructural examination at the triple point region, which is in contradiction with the FC, RC models, it is concluded that these simplified models, although remarkable in their ability to predict lattice relations in certain cases, are not applicable to regions of high strain accommodation such as the triple grain boundary region or to grains of small size such as exist in ordinary polycrystalline metallic materials. |
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