论文信息 - On the presence of super lattice intrinsic stacking faults in plastically deformed Ni3Al

On the presence of super lattice intrinsic stacking faults in plastically deformed Ni3Al

Abstract Superlattice intrinsic stacking faults (SISFs) have been observed in Ni3Al polycrystals deformed in compression between room temperature and 800°C. A detailed weak-beam analysis indicates that the SISFs originate at a screw partial with a Burgers vector of 1/2〈110〉. Starting from the stable dissociation into two partials with collinear Burgers vectors and with an antiphase boundary stabilized on {001}, one of the two 1/2〈110〉 partials may split under the effect of a high local stress into an edge Shockley and a partial with a Burgers vector of 1/2〈112〉. The latter produces a SISF as it escapes from its initial position in a {111} plane. Calculations of the total energy of the threefold dissociation shows the presence of a secondary minimum when the 1/3〈112〉 partial lies between 25 and 50 nm from the Shockley partial, in good agreement with the weak-beam observations. However, the SISFs exhibit large deviations from this equilibrium distance when they result from a deformation at low temperature a...

P. Veyssiére | P. Beauchamp | J. Douin

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