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Advances in Materials Science and Engineering
Volume 2014 (2014), Article ID 746470, 6 pages
http://dx.doi.org/10.1155/2014/746470
Research Article

Influence of Surface Modification of Alumina on Improvement of Wetability in Aluminium Matrix Composite

1Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
2Department of Advanced Materials and New Energies, Iranian Research Organization for Science and Technology, Tehran 3353-5111, Iran

Received 24 October 2013; Revised 26 January 2014; Accepted 16 February 2014; Published 19 March 2014

Academic Editor: Tao Zhang

Copyright © 2014 Alireza Samiee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In this research, aluminium powder (50 wt%) and alumina (50 wt%) were first milled at a specific ball-to-powder ratio in a high-energy planetary mill at different times to manufacture Al-Al2O3 composite. Then, the capsules of powdery composites (Al-Al2O3)CP produced at the milling stage were added to aluminium melt and cast through ex situ. Scanning electron microscope SEM was used to study the morphology of the capsules and the microstructure of the produced composite. The percentage of powdery composite capsules and reinforcing particles present in the microstructure of Al-Al2O3 composite was measured by Image Tool software. The results of the tests showed that, by optimizing the milling time to 5 hours, the alumina particles are sufficiently placed in the matrix of the capsules; on the other hand, alumina particles are also properly coated with aluminium powder. When these capsules are added to aluminium melt, the rate of the wetting of alumina particles greatly increases and accordingly the percentage of the reinforcing particles in the cast composite matrix increases dramatically. By surface modification and accordingly increasing percentage of Al2O3, the tensile strength increases and the tensile strength of the composites is higher than that of the matrix alloy.