Production Engineering

, Volume 8, Issue 4, pp 443–451 | Cite as

Reprocessing of AW2007, AW6082 and AW7075 aluminium chips by using sintering and forging operations

  • Bernd-Arno Behrens
  • Conrad Frischkorn
  • Martin BonhageEmail author
Production Process


Since its discovery in the late Nineteenth century aluminium becomes an important construction material due to its good mechanical properties such as sufficient strength at low density. Additional advantages are high corrosion resistance as well as low manufacturing forces. Apart from this, aluminium is still very expensive to produce. The energy consumption of the production process is at least twice as much as for steel. Most of the energy consumption takes place at the electrolyse process while aluminium oxide (Al2O3)—recovered from natural bauxite—is divided into unalloyed aluminium named “primary aluminium” and CO2. Contrary to the expensive production of primary aluminium the energy consumption of the recycling process of used aluminium also known as “secondary aluminium” is considerably lower. Given this huge effort in producing primary aluminium, the recycling of aluminium is an important economic and ecological approach. The common recycling method for aluminium is to melt it in a furnace. Except from small-sized scrap like chips, this is an overall efficient recycling method for most aluminium scraps. It can be observed that especially chips suffer high material losses mostly due to contaminants from the production process (cooling lubricant, oil etc.), fire losses (oxidation), slag and unadapted furnace settings. For this reason, several researches examine alternative recycling processes to avoid a melting process and minimize material losses. In this investigation a new non-melting aluminium recycling approach will be validated. For this purpose various chip pressings (turning, milling, sawing) are forged with an upsetting press. It will be shown that it is possible to generate a solid consolidation without pores in areas of high material movement. Furthermore, the effect of a previous sintering operation will be examined.


Aluminium alloy scrap Recycling Aluminium chips Forging 


  1. 1.
    Gronostajski J, Matuszak A (1999) The recycling of metals by plastic deformation: an example of recycling of aluminium and its alloys chips. J Mater Process Technol 92–93:35–41CrossRefGoogle Scholar
  2. 2.
    Drossel G, Lehnert W, Friedrich S, Kammer C, Liesenberg O (2009) Aluminium Taschenbuch Band 2: Umformung von Aluminium-Werkstoffen, Gießen von Aluminiumteilen, Oberflächenbehandlung von Aluminium, Recycling und Ökologie, Alu Media GmbH, DüsseldorfGoogle Scholar
  3. 3.
    Amini Mashhadi H, Moloodi A, Golestanipour M, Karimi EZV (2009) Recycling of aluminium alloy turning scrap via cold pressing and melting with salt flux. J Mater Process Technol 209:3138–3142CrossRefGoogle Scholar
  4. 4.
    Prillhofer R, Prillhofer B, Antrekowitsch H (2008) Verwertung von Reststoffen beim Aluminium-Recycling. BHM Berg-und Hüttenmännische Montshefte 153(3):103–108CrossRefGoogle Scholar
  5. 5.
    Schröder D (2007) Zweikammer Schmelzofen mit integrierter Nachverbrennung. Int Alum J 9(2007):67–69Google Scholar
  6. 6.
    Stern M (1945) U.S. Patent 2,391,752Google Scholar
  7. 7.
    Fogagnolo JB, Ruiz-Navas EM, Simon MA, Martinez MA (2003) Recycling of aluminium alloy and aluminium matrix composite chips by pressing and hot extrusion. J Mater Process Technol 143–144(2003):792–795CrossRefGoogle Scholar
  8. 8.
    Schikorra M, Pantke K, Tekkaya AE, Biermann D (2008) Re-use of AA6060, AA6082, and AA7075 aluminum turning chips by hot extrusion, ICTP 2008 (The 9th international conference on technology of plasticity), Gyeongju, Korea: pp 902–907Google Scholar
  9. 9.
    Watanabe H, Moriwaki K, Mukai T, Ishikawa K, Kohzu M, Higashi K (2001) Consolidation of machined magnesium alloy chips by hot extrusion utilizing superplastic flow. J Mater Sci 36:5007–5011CrossRefGoogle Scholar
  10. 10.
    Luangvaranunt T, Kondoh K, Aizawa T (2002) A novel process to form al-12 mass%Si bulk material from machined chips using bulk mechanical alloying. Mater Trans 43(5):1178–1182CrossRefGoogle Scholar
  11. 11.
    Haase M, Khalifa Ben N, Tekkaya AE, Misiolek WZ (2012) Improving mechanical properties of chip-based aluminum extrudates by integrated extrusion and equal channel angular pressing (iECAP). Mater Sci Eng A539:194–204CrossRefGoogle Scholar
  12. 12.
    Luo P, McDonald DT, Zhu SM, Palanisamy S, Dargusch MS, Xia K (2012) Analysis of microstructure and strengthening in pure titanium recycled from machining chips by equal channel angular pressing using electron backscatter diffraction. Mater Sci Eng, A 538:252–258CrossRefGoogle Scholar
  13. 13.
    Suzuki K, Huang X, Watazu A, Shigematsu I, Saito N (2007) Recycling of 6061 aluminium alloy cutting chips using hot extrusion and hot rolling. Mater Sci Forum 544–545:443–446CrossRefGoogle Scholar
  14. 14.
    Drucker DC, Prager W (1952) Soil mechanics and plastic analysis for limit design. Q Appl Math 10(2):157–165zbMATHMathSciNetGoogle Scholar
  15. 15.
    Kraft T, Riedel H, Stingl P, Wittig F (1999) Finite element simulation of die pressing and sintering. Adv Eng Mater 1(2):107–109CrossRefGoogle Scholar
  16. 16.
    Behrens BA, Bouguecha A, Hanini K (2004) Ermitteln der Versagenslinie von Aluminiumpulver für das Drucker-Prager-Kappenmodell, Werkstattstechnik online Jahrgang 94, H.10, pp 510-511Google Scholar
  17. 17.
    Grüner M, Merklein M (2013) Basic experimental and numerical investigations on chip pressing. Key Eng Mater 554–557:630–637CrossRefGoogle Scholar
  18. 18.
    Denkena B, Tönshoff HK (2011) Spanen Grundlagen 3., bearb. und erw. Aufl., Springer, Berlin HeidelbergGoogle Scholar
  19. 19.
    Doege E, Behrens BA (2007) Handbuch Umformtechnik Grundlagen, Technologien, Maschinen. Springer, BerlinGoogle Scholar
  20. 20.
    Schatt W, Wieters KP, Kieback B (2007) Pulvermetallurgie Technologien und Werkstoffe. Springer, BerlinGoogle Scholar
  21. 21.
    Gaštan E (2012) Einfluss von Werkzeugschwingungen auf das Verdichtungsverhalten metallischer Pulver beim Matrizenpressen. Dissertation, Leibniz Universität HannoverGoogle Scholar

Copyright information

© German Academic Society for Production Engineering (WGP) 2014

Authors and Affiliations

  • Bernd-Arno Behrens
    • 1
  • Conrad Frischkorn
    • 1
  • Martin Bonhage
    • 1
    Email author
  1. 1.Institute of Forming Technology and Machines (IFUM)Leibniz Universität HannoverGarbsenGermany

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