Abstract
The influence of the cooling rate on the extent of precipitation hardening of cast aluminum alloy (ADC12) was investigated experimentally. This study explored the cooling rate of the solidification of Cu in the α-Al phase to improve the mechanical properties of ADC12 after an aging process (Cu based precipitation hardening). The solid solution of Cu occurred in the α-Al phases during the casting process at cooling rates exceeding 0.03 °C/s. This process was replaced with a solid solution process of T6 treatments. The extent of the solid solution varied depending on the cooling rate; with a higher cooling rate, a more extensive solid solution was formed. For the cast ADC12 alloy made at a high cooling rate, high precipitation hardening occurred after low-temperature heating (at 175 °C for 20 h), which improved the mechanical properties of the cast Al alloys. However, the low-temperature heating at the higher temperature for a longer time decreased the hardness due to over aging. Keywords: Aluminum alloy, Casting, Precipitation, Solid solution, Aging, Solidification rate
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Bibliography
[1] Sepehrband, P., Mahmudi, R. & Khomamizadeh, F. (2005). Effect of Zr addition on the aging behavior of A319 aluminum cast alloy. Scripta Materialia. 52(4), 253-257.
[2] Rana, G., Zhoua, J.E. & Wang, Q.G. (2008). Precipitates and tensile fracture mechanism in a sand cast A356 aluminum alloy. Journal of Materials Processing Technology. 207(1-3), 46-52.
[3] Tian, L., Guo, Y., Li, J., Xia, F., Liang, M. & Bai, Y. (2018). Effects of solidification cooling rate on the microstructure and mechanical properties of a Cast Al-Si-Cu-Mg-Ni piston alloy. Materials. 11(7), 1230.
[4] Choi, S.W., Kima, Y.M., Leea, K.M., Cho, H.S., Hong, S.K., Kim, Y.C., Kang, C.S. & Kumai, S. (2014). The effects of cooling rate and heat treatment on mechanical and thermal characteristics of Al–Si–Cu–Mg foundry alloys. Journal of Alloys and Compounds. 617, 654-659.
[5] Dobrzański, L.A., Maniara, R., Sokołowski, J. & Kasprzak, W. (2007). Effect of cooling rate on the solidification behavior of AC AlSi7Cu2 alloy. Journal of Materials Processing Technology. 191(1-3), 317-320.
[6] Shabel, B.S., Granger, D.A., Trucker, W.G. (1992). Friction and wear of aluminum-silicon alloys. In P.J. Blau (Eds.), ASM Handbook: Friction, Lubrication, and Wear Technology (pp. 785-794), ASM International.
[7] Son, S.K., Takeda, M., Mitome, M., Bando, Y. & Endo,T. (2005). Precipitation behavior of an Al–Cu alloy during isothermal aging at low temperatures. Materials Letters. 59(6), 629-632.
[8] Wen-jun, T., Lin, Q. & Pi-xiang, Q. (2007). Study on heat treatment blister of squeeze casting parts. China Foundry. 4(2), 108-111.
[9] Okayasu, M., Sahara, N. & Mayama, K. (2021). Effect of microstructural characteristics on mechanical properties of cast Al–Si–Cu alloy controlled by Na. Materials Science and Engineering. A (in press).
[10] Hamasaki, M. & Miyahara, H. (2013). Solidification microstructure and critical conditions of shrinkage porosity generation in die casting process of JIS-ADC12 (A383) alloy. Materials Transactions. 54(7), 1131-1139.
[11] Kamio, A. (1996). Refinement of solidification structure in aluminum alloys. Japan Foundry Engineering Society. 68, 1075-1083.
[12] Okayasu, M. & Go, S. (2015). Precise analysis of effects of aging on mechanical properties of cast ADC12 aluminum alloy. Materials Science and Engineering. A 638, 208-218.
[13] David, S.A. & Vitek, J.M. (1989). Correlation between solidification parameters and weld microstructures. International Materials Reviews. 34(1), 213-245.
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