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 ENG  Vol.4 No.9 , September 2012
Correlation between Hardness, Structure and Electrochemical Performance of an AlZnMnMg Alloy
Abstract: In this work the structural changes induced by aged treatment have shown a connection with differences of hardness and electrochemical performance. Al-base alloys have been investigated by means of Vickers hardness, X-ray diffraction, scanning electron and short-term electrochemical test. X-ray diffraction result reveals the formation of (MgZn)49Al32 phase for two conditions, the first one is when the magnesium content is upper to 5.49% in as-cast condition and the second one after the thermal treatment carried out at 450?C for 5 h. In addition, the hardness and electrochemical performance has been influenced by the presence and quantity of the (MgZn)49Al32 phase. The addition of magnesium alloying modifies the microstructure, increases the content of (MgZn)49Al32 phase and provides a localized corrosion which conduced to the breakdown of the oxide film (?-Al2O3) formed on the Al alloy surface.
Cite this paper: S. Valdez, B. Campillo and J. Islas, "Correlation between Hardness, Structure and Electrochemical Performance of an AlZnMnMg Alloy," Engineering, Vol. 4 No. 9, 2012, pp. 590-597. doi: 10.4236/eng.2012.49075.
References

[1]   T. Pervez, S. Z. Qamar, A. C. Seibi and F. K. Al-Jahwari, “Use of SET in Cased and Open Holes: Comparison between Aluminum and Steel,” Materials Design, Vol. 29, No. 4, 2008, pp. 811-817. doi:10.1016/j.matdes.2007.01.009

[2]   H. K. Rafi, G. D. J. Ram, G. Phanikumar and K. P. Rao, “Microstructure and Tensile Properties of Friction Welded Aluminum Alloy AA7075-T6,” Materials Design, Vol. 31, No. 5, 2010, pp. 2375-2380. doi:10.1016/j.matdes.2009.11.065

[3]   S. Valdez, B. Mena, J. Genesca and J. A. Juárez-Islas, “Evaluation of an Al-Zn-Mg-Li Alloy/Potential Candidate as Al-Sacrificial Anode,” Journal Materials Engineering Performance, Vol. 10, No. 5, 2001, pp. 596-601. doi:10.1361/105994901770344755

[4]   H. Sina, M. Emamya, M. Saremi, A. Keyvani, M. Mahta and J. Campbell, “The Influence of Ti and Zr on Electrochemical Properties of Aluminum Sacrificial Anodes,” Materials Science Engineering A, Vol. 431, No. 1-2, 2006, pp. 263-276. doi:10.1016/j.msea.2006.06.011

[5]   S. M. A. Shibli, “Surface Catalysis Based on Ruthenium Dioxide for Effective Activation of Aluminium Sacrificial Anodes,” Corrosion Science, Vol. 46, No. 4, 2004, pp. 819-830. doi:10.1016/S0010-938X(03)00038-6

[6]   F. Eckermanna, T. Suter, P. J. Uggowitzer, A. Afseth and P. Schmutz, “The Influence of MgSi Particle Reactivity and Dissolution Processes on Corrosion in Al-Mg-Si Alloys,” Electrochemical Acta, Vol. 54, No. 2, 2008, pp. 844-855. doi:10.1016/j.electacta.2008.05.078

[7]   G. Mrówka-Nowotnik and J. Sieniawski, “Influence of heat Treatment on the Microstructure and Mechanical Properties of 6005 and 6082 Aluminium Alloys,” Journal Materials Processing Technique, Vol. 162-163, 2005, pp. 367-372. doi:10.1016/j.jmatprotec.2005.02.115

[8]   F. Mondolfo, “Aluminium Alloys: Structure and Properties,” Metallurgical Reviews, Vol. 16, 1971, p. 953.

[9]   Z. H. Li, B. Q. Xiong, Y. A. Zhang, B. H. Zhu, F. Wang and H. W. Liu, “Investigation of Microstructural Evolution and Mechanical Properties during Two-Step Ageing Treatment at 115?C and 160?C in an Al-Zn-Mg-Cu Alloy Pre-Stretched Thick Plate,” Materials Characterization, Vol. 59, No. 3, 2008, pp. 278-282. doi:10.1016/j.matchar.2007.01.006

[10]   I. J. Polmear, “Light Alloys, Metallurgy of the Light Metals,” 2nd Edition, Arnold, London, 1989, p. 21.

[11]   G. L. Song, B. Johannesson, S. Hapugoda and D. StJohn, “Galvanic Corrosion of Magnesium Alloy AZ91D in Contact with an Aluminium Alloy, Steel and Zinc,” Corrosion Science, Vol. 46, No. 4, 2004, pp. 955-977. doi:10.1016/S0010-938X(03)00190-2

[12]   H. Ezuber, A. El-Houd and F. El-Shawesh, “A Study on the Corrosion Behavior of Aluminum Alloys in Seawater,” Materials Design, Vol. 29, No. 4, 2008, pp. 801-805. doi:10.1016/j.matdes.2007.01.021

[13]   M. Talavera, S. Valdez, J.A. Juarez-Islas, B. Mena and J. Genesca, “EIS Testing of New Aluminium Sacrificial Anode,” Journal of Applied Electrochemical, Vol. 32, No. 8, 2002, pp. 807-903. doi:10.1023/A:1020547508321

[14]   S. P. Ringer and K. Hono, “Microstructural Evolution and Age Hardening in Aluminium Alloys: Atom Probe FieldIon Microscopy and Transmission Electron Microscopy Studies,” Materials Characterization, Vol. 44, No. 1-2, 2000, pp. 101-131. doi:10.1016/S1044-5803(99)00051-0

[15]   K. Mills, J. R. Davis and J. D. Destefani, “Metallography and Microstructure,” ASM Handbook, Vol. 9, 1998, p. 354.

[16]   DNV Recommended Practice RP B401, “Cathodic Protection Design,” Det Norske Veritas Industry As, Hovik, 1993.

[17]   ASTM D1141-98, “Standard Practice for the Preparation of Substitute Ocean Water,” Annual Book of ASTM Standards, Philadelphia, 2004.

[18]   G. Bergmaiv, J. L. T. Waugh and L. Pauling, “The Crystal Structure of the Metallic Phase Mg32(A1, Zn)49,” Acta Crystallographica, Vol. 10, 1957, pp. 254-259. doi:10.1107/S0365110X57000808

[19]   V. Raghavan, “Al-Mg-Zn (Aluminum-Magnesium-Zinc),” Journal of Phase Equilibria, Vol. 28, No. 2, 2007, pp. 203-208. doi:10.1007/s11669-007-9029-6

[20]   B. D. Cullity, “Elements of X-Ray Diffraction,” 2nd Edition, Addison-Wesley Publishing Company, Inc., Boston, 1978.

[21]   L. A. Dobrzanski, T. Tanski, J. Trzaska and L. Cizek, “Modelling of Hardness Prediction of Magnesium Alloys Using Artificial Neural Networks Applications,” Journal of Achievements in Materials and Manufacturing Engineering, Vol. 26, No. 2, 2008, pp. 187-190.

 
 
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