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Optimization of Artificial Ageing Time and Temperature on Evaluation of Hardness and Resistivity of Al-Si-Mg (Cu or/& Ni) Alloys

Authors: A. Hossain, A. S. W. Kurny


The factors necessary to obtain an optimal heat treatment that influence the hardness and resistivity of Al-6Si-0.5Mg casting alloys with Cu or/and Ni additions were investigated. The alloys were homogenised (24hr at 500oC), solutionized (2hr at 540oC) and artificially ageing at various times and temperatures. The alloys were aged isochronally for 60 minutes at temperatures up to 400oC and isothermally at 150, 175, 200, 225, 250 & 300oC for different periods in the range 15 to 360 minutes. The hardness and electrical resistivity of the alloys were measured for various artificial ageing times and temperatures. From the isochronal ageing treatment, hardness found maximum ageing at 225oC. And from the isothermal ageing treatment, hardness found maximum for 60 minutes at 225oC. So the optimal heat treatment consists of 60 minutes ageing at 225oC.

Keywords: Ageing, Hardness, resistivity, Al-Si-Mg alloy

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[1] G. Timmermans, and L. Froyen, "Fretting wear behavior of hypereutectic P/M Al–Si in oil environment,” Wear, vol. 230(2), 1999, pp.105-117.
[2] L. Lasa, and J. M. Rodriguez-ibabe, "Effect of composition and processing route on the wear behaviour of Al-Si alloys,” Script. Mat., vol.46 (2), 2002, pp.477-481.
[3] K. Fanxiao, "Study on Hypereutectic Al-Si Piston Alloy,” (Dissertation) Chongqing, College of Mechanical Engineering, Chongqing University, 2007.
[4] D. Emadi, V. Whiting, M. Sahoo, J.H. Sokolowski, P. Burke, and M. Hart, "Optimal heat treatment of A356.2 alloy,” Light Metals, TMS, 2003, pp.983-989.
[5] I. J. Polmear, Light Alloys, Metallurgy of the Light Metals, 2nd Ed., Edward Arnold, London, 1989, p. 95.
[6] L. Lasa, and J. M. Rodrigues-ibade, "Wear behaviour of eutectic and hypereutectic Al-Si-Cu-Mg casting alloys tested against a composite brake pad,” Materials Science and Engineering A, vol. 363(1−2), 2003, pp.193−202.
[7] W. Reif, J. Dutkiewicz, R. Ciach, S. Yu, and J. Krol, "Effect of aging on the evolution of precipitate in Al-Si-Cu-Mg alloys,” Materials Science and Engineering A, vol.234−236(30), 1997, pp. 165−168.
[8] X. Lir, R. D. Li, Y. H. Zhao, L. Z. He, C. X. Li, H. R. Guan, and Z. Q. Hu, "Age-hardening behavior of cast Al-Si base alloy,” Materials Letters, vol.58(15), 2004, pp.2096−2101.
[9] H. Kezhun, Y. Fuxiao, Z. Dazhi, and Z. Liang, "Microstructural evolution of direct chill cast Al-15.5Si-4Cu-1Mg-1Ni-0.5Cr alloy during solution treatment,” China Foundry, vol.8(3), 2011, pp. 264-268.
[10] J. H. Kim, E. Kobayashi and T. Sato, "Effects of Cu Addition on Behavior of Nanoclusters during Multi-Step Aging in Al-Mg-Si Alloys,” Materials Transactions, vol.52(5), 2011. pp. 906 – 913.
[11] A.R. Eivani, H. Ahmed, J. Zhou, and J. Duszczyk, "Correlation between Electrical Resistivity, Particle Dissolution, Precipitation of Dispersoids, and Recrystallization Behavior of AA7020 Aluminum Alloy,” Metallurgical and materials Transactions A, vol.40A, 2009, pp.2435—2446.