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2035 |
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Tuesday, May 04, 2010, Sophia Room 2:40 PM Young Scientists |
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Consolidation of Al2O3/Al nanocomposite powder by cold spray |
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Dominique Poirier* / National Research Council of Canada, Canada Jean-Gabriel Legoux / Industrial Materials Institute, National Research Council of Canada , Canada Robin Drew/ Concordia University, Canada Raynald Gauvin/ McGill University, Canada |
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Due to their lightweight and high specific strength, aluminum matrix composites are attractive structural materials for various domains such as automotive and aerospace applications. Recently, several papers have reported an increase in aluminum composite strength together with an improvement in ductility when the reinforcement size goes from microscale to nanoscale. However, the processing of those nanocomposites is difficult due to the agglomeration tendency of the nanoreinforcements. While high energy mechanical milling was found to eliminate clustering issue for several nanocomposites , milled powder is difficult to consolidate by tradtitional methods such as hot pressing or extrusion. Some successful uses of cold spray to produce nanocomposites have been published. The combination of mechanical milling and cold spray offers several advantages. As the reinforcement is embedded in the matrix powder, there is no loss of reinforcement during spraying. Furthermore, cold spray preserves the nanograins obtained from mechanical milling in the coating due to the low temperature involved. The objective of this study is to assess the potential of cold spray to consolidate Al2O3-Al nanocomposite powder obtained from mechanical milling. The spraying parameters have first been adjusted for milled powders to account for their flaky morphology and high hardness. The microstructure and properties of the resulting coatings were then studied. |