Microstructure and high temperature wear of the aluminum matrix composites fabricated by reaction from Al-ZrO₂-B elemental powders

Abstract

The microstructural evolution and high temperature wear characteristics of aluminum matrix composites fabricated by reaction of Al-ZrO 2-B elemental powders were explored. The amount of the Al 3Zr phase in the composites decreased with the increase of the B/ZrO 2 mole ratio. When the B/ZrO 2 mole ratio reached 2, the Al 3Zr components almost diminished and the resultant composites consisted of primarily fine α-Al 2O 3 and ZrB 2 particles. At test temperature of 373K and the applied load of 20N, the wear rate of the composites increased and arrived at the maximum value before decreasing with the further increase of sliding velocity. However, when the test temperature was reached to 473K, the wear rate decreased constantly with the increase of sliding velocity. With the increase of B/ZrO 2 molar ratio, both the wear rate and the friction coefficient of the composites decreased, while the subsurface deformation zone increases. The findings help us to broaden the application of aluminum matrix composites in areas where high temperature wear is a limiting factor. © 2011 Elsevier B.V..