Acta Metallurgica Sinica (English Letters) ›› 2014, Vol. 27 ›› Issue (5): 944-950.DOI: 10.1007/s40195-014-0157-9

• Orginal Article • Previous Articles     Next Articles

Preparation of High-Strength Al-Mg-Si/Al2O3 Composites with Lamellar Structures Using Freeze Casting and Pressureless Infiltration Techniques

Shen Ping(), Xi Juwei, Fu Yujie, Shaga Alateng, Sun Chang, Jiang Qichuan   

  1. Key Laboratory of Automobile Materials (Ministry of Education), Department of Materials Science and Engineering, Jilin University, Changchun, 130025, China
  • Received:2014-03-07 Revised:2014-06-19 Online:2014-10-07 Published:2014-11-13

Abstract:

Lamellar porous alumina scaffolds with the initial solid loadings of 20, 25, and 30 vol% were prepared by freeze casting using 5 μm alumina powders. With the addition of 3 wt% MgO-Al2O3-SiO2 nanopowders in a eutectic composition as sintering aid, the maximum compressive strength of the sintered scaffolds reached (64 ± 2) MPa after sintering at 1,773 K for 2 h. The lamellar porous scaffolds were then filled with a molten Al-12Si-10 Mg alloy (in wt%) by pressureless infiltration at 1,223 K in a N2 atmosphere, yielding the shell-like structure of the composites. The compressive strength of the upper part composite with the initial 30 vol% solid loading reached (1,190 ± 50) MPa, which was about 3.5 times as large as that of the matrix alloy.

Key words: Biomimetic, Metal-matrix composites, Porous materials