Atomic pillar-based nanoprecipitates strengthen AlMgSi alloys

Science

Volumn 312, Issue 5772, 2006, Pages 416-419

  Chen, J H ^a   Costan, E ^a   Van Huis, M A ^a   Xu, Q ^a   Zandbergen, H W ^a  

^a DELFT UNIVERSITY OF TECHNOLOGY   (Netherlands)

Author keywords

[No Author keywords available]

Indexed keywords

ALUMINUM ALLOYS; ANNEALING; COMPOSITION; ELECTRON MICROSCOPY; INTERMETALLICS; MORPHOLOGY; ONE DIMENSIONAL; OPTICAL RESOLVING POWER;

ALMGSI ALLOYS; ALUMINUM MATRIX; COMPOSITIONAL CHANGES; STRUCTURAL CHANGES;

NANOSTRUCTURED MATERIALS;

ALUMINUM; MAGNESIUM; NANOPARTICLE; SILICON;

ALLOY; ALUMINUM; ANNEALING; ELECTRON MICROSCOPY; PRECIPITATION (CHEMISTRY);

ARTICLE; ATOM; CHEMICAL COMPOSITION; CHEMICAL STRUCTURE; ELECTRON MICROSCOPY; HARDNESS; HEAT TREATMENT; MATERIALS; MORPHOLOGY; MOTOR VEHICLE; PRECIPITATION; PRIORITY JOURNAL;

EID: 33645961278     PISSN: 00368075     EISSN: 10959203     Source Type: Journal    
DOI: 10.1126/science.1124199     Document Type: Article

References (27)

1. A. Guinier, Nature 142, 569 (1938).
2. G. D. Preston, Philos. Mag. 26, 855 (1938).
3. For automotive outer panel application, a characteristic two-step age-hardening process is beneficially employed for AlMgSi alloys (26), in which the "seeds" of the precipitates are prepared with appropriate pre-aging in Al factories, whereas the effective hardening precipitates will form rapidly upon a short annealing (paint bake cycles) in car manufacturing plants. After pre-aging, the alloys must (i) be sufficiently soft for good formability and (ii) form certain particles for the quickbake hardening response upon the second heating.
4. L. Zhuang et al., Proceedings of the 2001 TMS Annual Meeting: Automotive Alloys, New Orleans, LA, 11 to 15 February (The Minerals, Metals, and Materials Society, New Orleans, LA, 2001), pp. 77-91.
5. M. Murayama, K. Hono, Acta Mater. 47, 1537 (1999).
6. G. A. Edwards, K. Stiller, G. L. Dunlop, M. J. Couper, Acta Mater 46, 3893 (1998).
7. P. Ringer, K. Hono, Mater. Charact. 44, 101 (2000).
8. H. W. Zandbergen, S. J. Andersen, J. Jansen, Science 277, 1221 (1997).
9. S. J. Andersen et al., Acta Mater. 46, 3283 (1998).
10. A. Perovic, D. D. Perovic, G. C. Weatherly, D. J. Lloyd, Scripta Mater. 41, 703 (1999).
11. C. D. Marioara, S. J. Andersen, J. Jansen, H. W. Zandbergen, Acta Mater. 49, 321 (2001).
12. C. Ravi, C. Wolverton, Acta Mater. 52, 4213 (2004).
13. G. Thomas, J. Inst. Met. 90, 57 (1961).
14. A. Guinier, Heterogeneities in Solid Solutions in Solid State Physics, F. Seitz, D. Turnbull, Eds. (Academic Press, London, 1959), vol. 9, pp. 293-398.
15. Materials and methods are available as supporting material on Science Online.
16. W. Coene, A. Jansen, Scanning Microsc. Suppl. 6, 379 (1992).
17. W. O. Saxton, Computer Techniques for Image Processing in Electron Microscopy (Academic Press, London, 1978).
18. W. Coene, G. Janssen, M. Op De Beeck, D. Van Dyck, Phys. Rev. Lett. 69, 3743 (1992).
19. C. L. Jia, A. Thust, Phys. Rev. Lett. 82, 5052 (1999).
20. W. Coene, A. Thust, M. Op de Beeck, D. Van Dyck, Ultramicroscopy 64, 109 (1996).
21. J. H. Chen, H. W. Zandbergen, D. Van Dyck, Ultramicroscopy 98, 81 (2004).
22. J. M. Cowley, Diffraction Physics (North-Holland Publishing, New York, 1981).
23. M. A. O'Keefe, R. Kilaas, Scanning Microsc. Suppl. 2, 225 (1988).
24. G. Kresse, J. Furthmuller, Phys. Rev. B 54, 11169 (1996).
25. Al is the energy of single bulk Al atoms. By k-point sampling and energy cutoff, it was ascertained that all the energy calculations are converged to <1 meV/atom (0.1 kJ/mol). Allowing both cell dimensions and atom positions to relax, the first-principles calculations also yield the free volume expansion ratios of different structures with respect to the Al lattice.
26. D. W. Pashley, M. H. Jacobs, J. T. Vietz, Philos. Mag. 16A, S1 (1967).
27. This research was carried out under the project number MC4.98047 of the Netherlands Institute for Metals Research. We thank K. Urban and M. Lentzen for the use of their aberration-corrected HRTEM facility; L. Zhuang for providing Al alloy samples; and I. M. Richardson for constructive discussions. J.H.C. would like to thank the National Science Fund of China (grant no. 10474102) for supporting part of the image analysis work.