Reinterpretation of precipitation behavior in an aged AlMgCu alloy
Source abstract
Abstract
Precipitation behavior of AlMgCu alloy during S phase aging sequence was studied with high resolution transmission electron microscope (HRTEM) and selected area diffraction (SAED) to determine the existence of S'' phase and GPBII zone in the alloy. Fast Fourier transform (FFT) patterns corresponding to GPB zones at different aging stages were observed, and it is revealed that S phase forms instantly after the GPB zone dissolves during aging. Both simulated HRTEM and SAED images illustrate that the S'' phase shows exactly the same characteristics as the S phase does, which is consistent with the experimental observations. A unique phase was also observed, which produced extra diffraction dots near the {012} positions in FFT pattern. This phase was once considered to be either S'' phase or GPBII zone, but none of them has been affirmed so far. In this work, it is found that the unique phase is a distorted and rotated S phase and that S'' phase or GPBII zone does not form during the aging. We further show that the S precipitation sequence of the aged AlMgCu alloy should be SSS → Cu-Mg clusters/GPB zone → S'/S(Al CuMg).
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Aluminum Alloy Microstructure Properties · Aluminum Alloys Composites Properties · Solidification and crystal growth phenomena
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (35)
Show source-provided references
1. Gao M, Feng CR, Wei RP (1998) An analytical electron microscopy study of constituent particles in commercial 7075-T6 and 2024-T3 alloys. Metall Mater Trans A 29:1145–115110.1007/s11661-998-0240-9 ↗
2. Wang SC, Starink MJ (2005) Precipitates and intermetallic phases in precipitation hardening Al–Cu–Mg–(Li) based alloys. Int Mater Rev 50:193–21510.1179/174328005X14357 ↗
3. Liu ZR, Chen JH, Wang SB, Yuan DW, Yin MJ, Wu CL (2011) The structure and the properties of S-phase in AlCuMg alloys. Acta Mater 59:7396–740510.1016/j.actamat.2011.08.009 ↗
4. Ratchev P, Verlinden B, De Smet P, Van Houtte P (1998) Precipitation hardening of an Al ± 4.2 wt% Mg ± 0.6 wt% Cu alloy. Acta Mater 46:3523–353310.1016/S1359-6454(98)00033-0 ↗
5. Ringer SP, Polmearb IJ, Sakurai T (1996) Effect of additions of Si and Ag to ternary Al–Cu–Mg alloys in the α + S phase field. Mater Sci Eng A 217–218:273–27610.1016/S0921-5093(96)10341-5 ↗
6. Reich L, Murayama M, Hono K (1998) Evolution of Ω phase in an Al–Cu–Mg–Ag alloy—a three-dimensional atom probe study. Acta Mater 46:6053–606210.1016/S1359-6454(98)00280-8 ↗
7. Gable BM, Shiflet GJ, Starke EA Jr (2004) The effect of Si additions on Ω precipitation in Al–Cu–Mg–(Ag) alloys. Scr Mater 50:149–15310.1016/j.scriptamat.2003.09.004 ↗
8. Marceau RKW, Sha G, Ferragut R, Dupasquier A, Ringer SP (2010) Solute clustering in Al–Cu–Mg alloys during the early stages of elevated temperature ageing. Acta Mater 58:4923–493910.1016/j.actamat.2010.05.020 ↗
9. Winkelman GB, Raviprasad K, Muddle BC (2007) Orientation relationships and lattice matching for the S phase in Al–Cu–Mg alloys. Acta Mater 55:3213–322810.1016/j.actamat.2007.01.011 ↗
10. Bagaryatsky YA (1952) Structural changes on aging Al–Cu–Mg alloys. Dokl Akad S.S.S.R. 87:397–401 and 559–562
11. Silcock JM (1960–1961) The structural ageing characterisation of Al–Cu–Mg alloys with copper:magnesium weigh ratio of 7:1 and 2:1. J Inst Met 89:203–210
12. Gouma PI, Lloyd DJ, Mills MJ (2001) Precipitation processes in Al–Mg–Cu alloys. Mater Sci Eng A 319–321:439–44210.1016/S0921-5093(01)01049-8 ↗
13. Ringer SP, Hono K, Polmear IJ, Sakural T (1996) Nucleation of precipitates in aged Al–Cu–Mg–(Ag) alloys with high Cu:Mg ratios. Acta Mater 44:1883–189810.1016/1359-6454(95)00314-2 ↗
14. Wang SC, Starink MJ (2007) Two types of S phase precipitates in Al–Cu–Mg alloys. Acta Mater 55:933–94110.1016/j.actamat.2006.09.015 ↗
15. Radmilovic V, Killas R, Dahnen U, Shiflet GJ (1999) Structure and morphology of S-phase precipitates in aluminum. Acta Mater 47:3987–399710.1016/S1359-6454(99)00259-1 ↗
16. Alekseev AA, Ananév VN, Ber LB, Kaputkin EY (1993) The structure of strengthening precipitates forming in high-temperature aging of Al–Cu–Mg alloys. Phys Met Metall 75:279–285
17. Kovarik L, Court SA, Fraser HL, Mills MJ (2008) GPB zones and composite GPB/GPBII zones in Al–Cu–Mg alloys. Acta Mater 56:4804–481510.1016/j.actamat.2008.05.042 ↗
18. Shih H, Ho N, Huang JC (1996) Precipitation behaviors in Al–Cu–Mg and 2024 aluminum alloys. Metall Mater Trans A 27:2479–249410.1007/BF02652342 ↗
19. Wolverton C (2001) Crystal structure and stability of complex precipitate phases in Al–Cu–Mg–(Si) and Al–Zn–Mg alloys. Acta Mater 49:3129–314210.1016/S1359-6454(01)00229-4 ↗
20. Charai A, Walther T, Alfonso C, Zahra AM, Zahra CY (2000) Coexistence of clusters, GPB zones, S″-, S′- and S-phases in an Al-0.9% Cu-1.4% Mg alloy. Acta Mater 48:2751–276410.1016/S1359-6454(99)00422-X ↗
21. Wang SC, Starink MJ (2004) The assessment of GPB2/S″ structures in Al–Cu–Mg alloys. Mater Sci Eng A 386:156–16310.1016/j.msea.2004.07.006 ↗
22. Wang SC, Starink MJ, Gao N (2006) Precipitation hardening in Al–Cu–Mg alloys revisited. Scr Mater 54:287–29110.1016/j.scriptamat.2005.09.010 ↗
23. Zahra AM, Zahra CY, Alfonso C, Charai A (1998) Comments on “cluster hardening in an aged Al-Cu-Mg alloys”. Scr Mater 39:1553–155810.1016/S1359-6462(98)00365-0 ↗
24. Wang GJ, Xiong BQ, Zhang YA (2011) Microstructural evolution during creep of a hot extruded 2D70Al-alloy. J Mater Sci 46:5090–5096. doi: 10.1007/s10853-011-5438-310.1007/s10853-011-5438-3 ↗
25. Kovarik L, Miller MK, Court SA, Mills MJ (2006) Origin of the modified orientation relationship for S(S″)-phase in Al–Mg–Cu alloys. Acta Mater 54:1731–174010.1016/j.actamat.2005.11.045 ↗
26. Ringer SP, Caraher SK, Polmear IJ (1998) Response to comments on clusters hardening in an aged Al–Cu–Mg alloy. Scr Mater 39:1559–156710.1016/S1359-6462(98)00364-9 ↗
27. Gao N, Starink MJ, Kamp N, Sinclair I (2007) Application of uniform design in optimisation of three stage ageing of Al–Cu–Mg alloys. J Mater Sci 42:4398–440510.1007/s10853-006-0659-6 ↗
28. Feng ZQ, Yang YQ, Huang B, Luo X, Li MH, Han M, Fu MS (2011) Variant selection and the strengthening effect of S precipitates at dislocations in Al–Cu–Mg alloy. Acta Mater 59:2412–242210.1016/j.actamat.2010.12.041 ↗
29. Shukla AK, Baeslack WA III (2009) Orientation relationships and morphology of S phase in friction stir welded Al–Cu–Mg alloy. J Mater Sci 44:676–67910.1007/s10853-008-3212-y ↗
30. Styles MJ, Hutchinson CR, Chen Y, Deschamps A, Bastow TJ (2012) The coexistence of two S (Al2CuMg) phases in Al–Cu–Mg alloys. Acta Mater 60:6940–695110.1016/j.actamat.2012.08.044 ↗
31. Kovarik L, Gouma PI, Kisielowski C, Court SA, Mills MJ (2004) Decomposition of an Al–Mg–Cu alloy—a high resolution transmission electron microscopy investigation. Mater Sci Eng A 387–389:326–33010.1016/j.msea.2004.03.087 ↗
32. Kovarik L, Gouma PI, Kisielowski C, Court SA, Mills MJ (2004) A HRTEM study of metastable phase formation in Al–Mg–Cu alloys during artificial aging. Acta Mater 52:2509–252010.1016/j.actamat.2004.01.041 ↗
33. Ratchev P, Verlinden B, De Smet P, Van Houtte P (1998) Effect of cooling rate and predeformation on the precipitation hardening of an Al-4.2wt.%Mg-0.6wt.%Cu alloy. Scr Mater 38:1195–120110.1016/S1359-6462(98)00024-4 ↗
34. Phillips VA (1975) High resolution electron microscope observations on precipitation in Al-3.0 wt% Cu alloy. Acta Metall 23:751–76710.1016/0001-6160(75)90058-9 ↗
35. Park JK, Ardell AJ (1983) Microstructures of the commercial 7075 Al alloy in the T651 and T7 tempers. Metall Trans 14A:1957–196510.1007/BF02662363 ↗