Microstructure and Mechanical Properties of Solution Treatment and Sr-Modification of Al-12%Si-1.5%Cu Alloy

Title & Authors
Microstructure and Mechanical Properties of Solution Treatment and Sr-Modification of Al-12%Si-1.5%Cu Alloy
Surin, Prayoon; Wong on, Jessada; Eidhed, Krittee;

Abstract
The purpose of this paper was to investigate the effects of solution treatment time and Sr-modification on the microstructure and property of the Al-Si piston alloy. It was found that as-cast microstructures of unmodified and Sr-modified Al-Si alloys consisted of a coarse acicular plate of eutectic Si, $\small{Cu_3NiAl_6}$ and $\small{Mg_2Si}$ phases in the $\small{{\alpha}}$-Al matrix but different in size and morphology. Both size and inter-particle spacing of Si particles were significantly changed by increasing of the solution treatment time. After a short solution treatment, the coarse acicular plate of the eutectic Si appears to be fragmented. Fully modified microstructure of Sr-modified alloy can reduce the solution treatment time to shorter compared to unmodified alloy. The maximum of a peak hardness value is found in the very short solution treatment of both Al-Si piston alloys. Compared to 10 h solution treatment, the solution treatment of 2-4 h is sufficient to achieve appropriate microstructures and hardness. The short solution treatment is very useful to increase the productivity and to reduce the manufacturing cost of the Al-Si piston alloys.
Keywords
Al-Si based alloy;Solution treatment;Sr-modification;
Language
English
Cited by
References
1.
Davis, J.R., ed. Aluminum and Aluminum Alloys, ASM International, 1993.

2.
R.X. Li, R.D. Li, Y.H. Zhao, L.Z. He, C.X. Li, H.R. Guan, Z.Q. Hu, Mater. Letter, 58, 2096-2101, 2004.

3.
M.M. Haque, M.A. Maleque, J. Meter. Pro. Tech. 77, 112-128, 1998.

4.
M. Zeren, Mater and Design, Article in press, 2006.

5.
D.L Zhang, L.H. Zheng, D.H. StJohn, J. Light Metal, 2, 27-36 2002.