Characterization of Al Metal Matrix Composites Produced by the Stir-Casting Method

Abstract

Composite materials which main constituent part is a metal are called Metal Matrix Composites (MMCs). The other compounds may be metals too, ceramics or even organics. They are well known for their excellent thermo-physical and mechanical properties. Reinforcement is used to improve different properties of the main material, such as wear resistance, hardness, fatigue resistance, friction coefficient, thermal conductivity and others. As a result, during the last years, MMCs have found a lot of application in automobile industry for the production of brakes and parts of engines and in aerospace industry for the production of structural components, as well as in electrical and electronic industry and in many other applications. MMCs can be produced by many ways, such as, powder blending and consolidation, foil diffusion bonding, electroplating, spray deposition, stir-casting and others. In this research stir-casting was used as processing technique for the production of Aluminum matrix composites reinforced by ceramic particles and iron. The morphologies of the produced composite materials were examined using optical and SEM microscopy. The compositions of their micro structural features were determined by EDX spectroscopy. The phases formed were determined by XRD techniques. In the tribological tests, under dry wear conditions, the as-produced composites materials showed significant increased resistance to wear compared to pure Al metal.