Effect of T6 Treatment on the Hardness of Carbon Nanotube Reinforced AA6061 Aluminium Alloy Matrix Composites

  • Dilemando Nagle Travessa
  • Matheus Pianassola
  • Mirian Glícea S. Carneiro
  • Marcela Lieblich


The development aluminum matrix composites, using carbon nanotubes as strengthening dispersion phase, is of great interest for the transport sector, that continuously demands high strength-low density materials for efficient structures.

In the present work, multiwall carbon nanotubes (MWCNT) were used to reinforce the AA6061 aluminium alloy. 1 and 2% (in weight) of MWCNT were mixed to the alloy powder by high-energy ball-milling process. The blended powder was consolidated by hot extrusion. The obtained composite bars were solution heat treated and aged to T6 temper, and characterized by optical and scanning electron microscopy, and by hardening testing. A typical wrought microstructure free of defects was obtained. Hardness of the composites was substantially increased for 2% MWCNT addition, milled for 10 h. The better performance for the composites blended at a higher milling time was supposed to be due to a better MWCNT dispersion. The effect of aging on the composite hardness was evaluated, and it was found that no benefits for the composite hardness were obtained after solution heat treatment followed by T6 aging according to SAE AMS2772 specification, when comparing to the as-extruded hardness values. Possible reasons for such composites behavior are discussed.


Aluminium matrix composite Carbon nanotubes High energy ball milling Hot extrusion Heat treatment 


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  1. [1]
    Thostenson ET, Renb Z, Choua TW. Advances in the science and technology of carbon nanotubes and their composites: a review. Composite Science and Technology. 2001;61:1899–1912.Google Scholar
  2. [2]
    Paradise M, Goswami T. Carbon nanotubes — Production and industrial applications. Materials. & Design. 2007;28:1477–89.CrossRefGoogle Scholar
  3. [3]
    Choi HJ, Shin JH, Bae DH. Grain size effect on the strengthening behavior of aluminum-based composites containing multi-walled carbon nanotubes. Composites Science and Technology. 2011;71:1699–1705.CrossRefGoogle Scholar
  4. [4]
    Poirier D, Gauvin R, Drew RAL. Structural characterization of a mechanically milled carbon nanotube/aluminum mixture. Composites: Part A. 2009;40:1482–89.CrossRefGoogle Scholar
  5. [5]
    Esawi AMK, Morsi K, Sayed A, Gawad AA, Borah P. Fabrication and properties of dispersed carbon nanotube-aluminum composites. Materials Science and Engineering A. 2009;508:167–173.CrossRefGoogle Scholar
  6. [6]
    Choi HJ, Kwon GB, Lee GY, Bae DH. Reinforcement with carbon nanotubes in aluminum matrix composites. Scripta Materialia. 2008;59:360–363.CrossRefGoogle Scholar
  7. [7]
    Deng C, Wang D, Zhang XX, Li AB. Processing and properties of carbon nanotubes reinforced aluminum composites. Materials Science and Engineering A. 2007;444:138–145.CrossRefGoogle Scholar
  8. [8]
    Bustamante RP, Guel IE, Madrid PA, Yoshida MM, Ramírez JMH, Sánchez RM. Microstructural characterization of Al-MWCNT composites produced by mechanical milling and hot extrusion. Journal of Alloys and Compounds. 2010;495:399–402.CrossRefGoogle Scholar
  9. [9]
    George R, Kashyap KT, Rahul R, Yamdagni S. Strengthening in carbon nanotube/aluminium (CNT/A1) composites. Scripta Materialia. 2005;53:1159–63.CrossRefGoogle Scholar
  10. [10]
    Morsi K, Esawi AMK, Lanka S, Sayed A, Taher M. Spark plasma extrusion (SPE) of ball-milled aluminum and carbon nanotube reinforced aluminum composite powders. Composites: Part A. 2010;41:322–326.CrossRefGoogle Scholar
  11. [11]
    Zhong R, Cong H, Hou P. F abrication of nano-Al based composites reinforced by single-walled carbon nanotubes. Carbon. 2003;41:848–851.CrossRefGoogle Scholar
  12. [12]
    Kwon H, Park DH, Silvain JF, Kawasaki A. Investigation of carbon nanotube reinforced aluminum matrix composite materials. Composites Science and Technology. 2010;70:546–550.CrossRefGoogle Scholar
  13. [13]
    Liao J, Tan M, Sridhar I. Spark plasma sintered multi-wall carbon nanotube reinforced aluminum matrix composites. Materials and Design. 2010;31:S96–S100.CrossRefGoogle Scholar
  14. [14]
    Laha T, Agarwal A. Effect of sintering on thermally sprayed carbon nanotube reinforced aluminum nanocomposite. Materials Science and Engineering A. 2008;480:323–332.CrossRefGoogle Scholar
  15. [15]
    Wang L, Choi H, Myoung J, Lee W. Mechanical alloying of multi-walled carbon nanotubes and aluminium powders for the preparation of carbon/metal composites. Carbon. 2009;47:3427–33.CrossRefGoogle Scholar
  16. [16]
    Deng CF, Zhang XX, Wang DZ, Lin Q, Li A. Preparation and characterization of carbon nanotubes/aluminum matrix composites. Materials Letters. 2007;61:1725–28.CrossRefGoogle Scholar
  17. [17]
    Deng CF. Zhang XX, Wang DZ, Ma XY. Calorimetric study of carbon nanotubes and aluminum. Materials Letters. 2007;61:3221–23.CrossRefGoogle Scholar
  18. [18]
    Kondoh K, Fukuda H, Umeda J, Imai H, Fugetsu B. Microstructural and mechanical behavior of MWCNTs reinforced Al-Mg-Si alloy composites in aging treatment. Carbon 2014; accepted manuscript — doi 10.1016/j.carbon.2014.01.013.Google Scholar
  19. [19]
    Aerospace Material Specification. Society of Automobile Engineers — SAE. AMS-QQ-A-200/8: Aluminum Alloy 6061, Bar, Rod, Shapes, Tube, and Wire, Extruded. SAE International; 2007.Google Scholar
  20. [20]
    Aerospace Material Specification. Society of Automobile Engineers — SAE AMS2772E: Heat Treatment of Aluminum Alloy Raw Materials. SAE International; 2008.Google Scholar
  21. [21]
    Dresselhaus MS, Dresselhaus G, Saito R, Jorio A. Raman spectroscopy of carbon nanotubes. Physics Reports. 2005;409:47–99.CrossRefGoogle Scholar
  22. [22]
    Antunes EF, Lobo AO, Corat EJ, Trava-Airoldi VJ, Martin AA, Verissimo C. Comparative study of first- and second order Raman spectra of MWCNT at visible and infrared laser excitation. Carbon. 2006;44:2202–11.CrossRefGoogle Scholar
  23. [23]
    MacKenzie DS, Totten GE. Analytical characterization of aluminium, steel, and superalloys. Boca Raton: CRC Press — Taylor & Francis Group; 2006.Google Scholar
  24. [24]
    Suryanarayana C. Mechanical alloying and milling. Progress in Materials Science. 2001;46:1–184.CrossRefGoogle Scholar
  25. [25]
    Arakawa S, Hatayama T, Matsugi K, Yanagisawa O. Effect of heterogeneous precipitation on age-hardening of A1203 particle dispersion Al-4% mass Cu composite produced by mechanical alloying. Scripta Materialia. 2000;42:755–760.CrossRefGoogle Scholar
  26. [26]
    Edwards G A, Stiller K, Dunlop G L, Couper M J. The precipitation Sequence in Al-Mg-Si Alloys. Acta Materialia 1998; 46: 3893–3904.CrossRefGoogle Scholar
  27. [27]
    Niranjani V L, Hari Kumar K C, Subramanya Sarma V. Development of high strength Al-Mg-Si AA6061 alloy through cold rolling and ageing. Materials Science and Engineering A 2009; 515: 169–174.CrossRefGoogle Scholar
  28. [28]
    Pogatscher S, Antrekowitsch H, Uggowitzer P J. Interdependent effect of chemical composition and thermal history on artificial aging of AA6061. Acta Materialia 2012; 60: 5545–5554.CrossRefGoogle Scholar
  29. [29]
    Corrochano J, Lieblich M, Ibáñez J. On the role of matrix grain size and particulate reinforcement on the hardness of powder metallurgy Al-Mg-Si/MoSi2 composites. Composites Science and Technology. 2009;69:1818–24.CrossRefGoogle Scholar

Copyright information

© TMS (The Minerals, Metals & Materials Society) 2015

Authors and Affiliations

  • Dilemando Nagle Travessa
    • 1
  • Matheus Pianassola
    • 1
  • Mirian Glícea S. Carneiro
    • 1
  • Marcela Lieblich
    • 2
  1. 1.Instituto de Ciência e TecnologiaUniversidade Federal de São PauloSão José dos Campos, SPBrazil
  2. 2.Centro Nacional de Investigaciones Metalurgicas Consejo Superior de Investigaciones CientificasCENIM-CSIC. AvdaMadridSpain

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