The Effect Of Homogenization Conditions On The Structure And Properties Of 6082 Alloy Billets

Open access


The paper presents the results of laboratory homogenization investigations of the 6082 grade alloys, differing in Mg and Si content. At the first stage, the microstructure of alloys was analysed after homogenization finished with water quenching. SEM/EDS investigations and DSC tests were applied to evaluate the dissolution of the Mg2Si particles and concentration of the main alloying additions in the grains interiors, depending on soaking conditions. In the case of alloy with lower Mg and Si content, homogenization the temperature of 535ºC for 8h is sufficient for significant Mg2Si particles dissolution. For the alloy with higher Mg and Si content, after homogenization the temperature of 550ºC for 8h, the amount of undissolved Mg2Si particles decreases visibly, compared to homogenization at 535ºC for 8h. However, an unfavourable tendency of dispersoids growth is observed and these soaking conditions are not found to be recommended.

At the second research stage, the influence of homogenization cooling rate on the size and distribution of the Mg2Si particles observed in the alloys microstructure was analysed. The ability of the Mg2Si particles, precipitated during various homogenization coolings, to rapid dissolution was estimated. For this purpose, the hardness after solution heat treatment with short annealing and ageing was determined and the DSC tests were performed. It was found, that cooling after homogenization at 315ºC/h is sufficient for precipitation of fine Mg2Si particles, which dissolve during subsequent rapid heating. Cooling at 40ºC/h, causes precipitation of Mg2Si phase in the form of large particles, unable for further fast dissolution.

[1] R. Shahani, R. Tirard-Collet, C. Sigli, Optimized 6xxx alloy Billet Performance: A Structured Approach, in: Proc. of 7th International Aluminum Extrusion Technology Seminar 2, 13 – 22 (2000).

[2] D. Marchive, High Extrudability Alloys in the 6000 Series, Light Metal Age 41, 3/4, 6 – 10 (1983).

[3] S.R. Claves, D.L. Elias, W.Z. Misiołek, Analysis of the lntermetallic Phase Transformation Occurring During Homogenization of 6xxx Aluminum Alloys, Materials Science Forum 396-402, 667-674, (2002)

[4] W. Kuijpers, W.H. Kool, P.T.G. Koenis, K.E. Nilsen, I. Todd, S. van der Zwaag, Assessment of different techniques for quantification of α-Al(FeMn)Si and β-AlFeSi intermetallics in AA 6xxx alloys, Materials Characterization 49, 409-420 (2003).

[5] A.J. Bryant, G.E. Macey, R.A.P. Fielding, Homogenization of Aluminium Alloy Extrusiom Billet. Part I: Furnance Design Principles and Application to AA6XXX Series Alloys, Light Metal Age 60, (3/4), 6-15 (2002).

[6] J. Røyset, M. Rødland, U. Tundal, O. Reiso, Effect of Alloy Chemistry and Process Parameters on the Extrudability and Recrystallization Resistance of 6082 Aluminum Alloy, in: Proc. of 9th International Aluminum Extrusion Technology Seminar & Exposition, (2008).

[7] O. Reiso, J.E. Hafsås, O. Sjothun, U. Tundal, The Effect of Cooling Rate After Homogenization and Billet Preheating Practice on Extrudability and Section Properties. Part 1: Extrudability and Mechanical Properties, in: Proc. of 6th International Aluminum Extrusion Technology Seminar 1, 1 – 10 (1996).

[8] A. Woźnicki, J. Richert, M. Richert, J. Woźnicka, Podatność wlewków ze stopów AlMgSi do wyciskania z przesycaniem na wybiegu prasy, Rudy Metale R. 48, 10-11, 468-473 (2003).

[9] M. Lefstad, O. Reiso, Metalurgical Speed Limitations During the Extrusion of AlMgSi-Alloys. Proc. of 6th International Aluminum Extrusion Technology Seminar1, 11 – 21 (1996).

[10] R.A. Ricks, N.C.Parson, H.L. Yiu, S.A.Court, Microstructural Optimisation for Extrusion Of 6063 Alloys, in: Proc. of 5th International Aluminum Extrusion Technology Seminar, 2, 57 – 69 (1992).

[11] S. Zając, B. Bengtsson, C. Jönsson, Influence of cooling after homogenization and reheating to extrusion on extrudability and final properties of AA6063 and AA6082 alloys,. Materials Science Forum 396-402, 399-404, (2002).

[12] Y. Birol, Homogenization of direct chill cast AlSi1MgMn billets, Int. J. Mater. Res. (formerly Z. Metallkd.) 105, (1), 75-82 (2014).

[13] A. Woźnicki, Najkorzystniejsze warunki wyciskania stopów AlMgSi z przesycaniem na wybiegu prasy, PhD thesis, AGH University of Science and Technology, Kraków (2004)

[14] J. Richert, Innowacyjne Metody Przeróbki Plastycznej Metali, Wydawnictwa AGH, Kraków (2010).

[15] N. Winjum, G.W. Newsted, A.R. Beevis, Continuous Homogenizing of 6xxx Alloy Aluminum Extrusion Billets at Alcoa-Intalco Works. Proc. of 7th International Aluminum Extrusion Technology Seminar 2, 115 – 123 (2000).

[16] J. Richert, M. Richert, J. Woźnicka, Z. Stec, Effect of Homogenization Cooling Rate and Microstructural Features of Al-Mg-Si Billets on Extrudability and Section Properties in the T5 Temper. Proc. of 7th International Aluminum Extrusion Technology Seminar 2, 105 – 113 (2000).

[17] G. Mrówka-Nowotnik, J. Sieniawski, A. Nowotnik, Intermetallic phase identification on the cast and heat treated 6082 aluminium alloy, Archives of Metallurgy and Materials, 51, (4), 599 – 603 (2006).

Archives of Metallurgy and Materials

The Journal of Institute of Metallurgy and Materials Science and Commitee on Metallurgy of Polish Academy of Sciences

Journal Information

IMPACT FACTOR 2016: 0.571
5-year IMPACT FACTOR: 0.776

CiteScore 2016: 0.85

SCImago Journal Rank (SJR) 2016: 0.347
Source Normalized Impact per Paper (SNIP) 2016: 0.740

Cited By


All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 471 357 36
PDF Downloads 215 169 13