Surface modification of an aluminium 2124 composite by eutectic alloying

The incorporation of a hard particular dispersion in a metal matrix results in a composite material with unique mechanical and tribological properties. However, once the composite has been fabricated the particular dispersion cannot be rearranged or modified. In this study, the surface of a 2124 aluminium metal matrix composite is modified by eutectic alloying with copper. The results show that by heat treating the composite at a temperature above the eutectic temperature for the Al-Cu system, the distribution of SiC particles can be altered. There is a significant movement of particles towards the surface of the composite and abrasive wear tests show better wear resistance than the unmodified surfaces. This change in wear behaviour is attributed to the absence of severe plastic deformation due to the increase in concentration of hard SiC particles within the surface. (C) 2001 Kluwer Academic Publishers.