Wear behavior of nano structured Al (Zn)/Al2O3 and Al (Zn)-4Cu/Al2O3 composite materials synthesized by mechanical and thermal process

Nanocrystalline materials have high potential for use in structural applications in which enhanced mechanical characteristics are required. Al-Zn/Al2O3 and Al-Zn-Cu/Al2O3 have been prepared via reaction sintering of partially reacted oxide mixtures derived from a high-energy ball milling process. The sintered samples have been characterized by XRD. Pin on disc type apparatus has been used for determining the wear rate. It is proposed in this study that the wear resistance of the milled composites is better than that of the unmilled composites, since Al2O3 particle size plays the main role in bearing the external load, and there is a good interfacial cohesion between Al2O3 particles and the matrix. On the basis of microscopic observations and analysis of the wear surface a change in mode of wear from mild to severe has been proposed at different loads. (C) 2007 Elsevier B.V. All rights reserved.