In situ (Al2O3+Al3Zr)np/Al nanocomposites synthesized by magneto-chemical melt reaction

In situ (Al2O3 + Al3Zr)(np)/Al nanocomposites were successfully prepared by magneto-chemical melt reaction from Al-Zr(CO3)(2) System. The solidification microstructure and mechanical properties are investigated. Results indicate that the size of majority in situ alpha-Al2O3 and Al3Zr particles is about 80 run, and the nano-sized particles are well distributed in the aluminum matrix. The ultimate tensile strength and yield strength of the nanocomposites are enhanced with the increasing of particulate volume fraction, and are markedly higher than that of (Al2O3 + Al3Zr)(p)/Al composites synthesized under zero magnetic field. When the particulate volume fraction is 8%, The ultimate tensile strength yield strength sigma y, elongation 6 and Vickers hardness of the (Al2O3 + Al3Zr)(np)/Al nanocomposites are 326.7 MPa, 245.6 MPa, 18.6% and 125, respectively. The principal strengthening mechanism for (Al2O3 + Al3Zr)np/Al nanocomposites may include Orowan strengthening, Grain-refined strengthening, Solid-solution strengthening and Dislocation strengthening. (C) 2007 Elsevier Ltd. All rights reserved.