Silicon carbide whisker reinforced aluminium composites–fabrication and properties

Abstract

A fabrication process for SiC whisker reinforced aluminium composites is being developed. Theftrst step involves preforming the SiC whisker and squeeze-infiltrating the molten metal into the preform. Secondary fabrication can involve a conventional hot metal working practice such as extrusion. Microscopic observations indicate that the distribution of whiskers is very homogeneous. In an aluminium alloy (AA 6061) matrix composite containing 17 vol.-% SiC whiskers, the Young's modulus is > 100 GPa and the tensile strength increases by ~ 50–70% above that of the matrix to 460 and 529 MN m⁻² in the cast and extruded products, respectively. The strength at elevated temperature and the wear resistance are also improved. These enhanced properties make the composite potentially suitable for a number of automotive applications. MST/574