Atomistic process of dislocation cross-slip in Ni{sub 3}Al
- Shanghai Jiao Tong Univ. (China). Inst. of Materials Science
In recent years, a great deal of interest has been given to the L1{sub 2} ordered intermetallic compound Ni{sub 3}Al because of its unusual flow behaviors. Based upon the measurements of mechanical properties and the observed dislocation configurations, several models have been proposed to explain the flow stress anomaly, including the anomalous increase of flow stress with temperature, the strain rate sensitivity, the pronounced orientation dependence and the tension/compression asymmetry. The most important common ground of these models is that the flow stress anomaly is the result of cross-slip of <110> superdislocations form {l_brace}111{r_brace} to {l_brace}100{r_brace} planes, forming so-called Kear-Wilsdorf (KW) locks. Computer simulations of superdislocation core structure in Ni{sub 3}Al indicate that the immobility of KW locks is due to the non-planar core structure of 1/2<110> superpartials which always spread their cores onto {l_brace}110{r_brace} planes other than the {l_brace}100{r_brace} antiphase boundary (APB) planes. However, up to now the authors are still unaware of how the cross-slip takes place. The purpose of the present study is to reveal the atomistic process of the cross-slip of 1/2<110> superpartials from {l_brace}111{r_brace} to {l_brace}100{r_brace} planes in L1{sub 2} ordered materials.
- OSTI ID:
- 438601
- Journal Information:
- Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 3 Vol. 36; ISSN 1359-6462; ISSN SCMAF7
- Country of Publication:
- United States
- Language:
- English
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