Whiskers Aluminum-matrix composites are reinforced with SiC whiskers, which are more costly than particles due to the following advantages. Single crystal whiskers have high tensile strength than other discontinuous reinforcements such as particles, polycrystalline flakes and chopped fibers. Standard metal working methods can orient whiskers in the metal-matrix. Extrusion,rolling,forging and superplastic forming can impart directional strength. Longitudinal tensile strength increases when the aluminum composite is extruded, since whisker tend to align along the die's axis as the material moves through.
Sheet rolling can import directional strength and cross rolling makes properties more uniform.
Superplastically formed horseshoes have been used where lightness and wear are a competitive edge. The overall improvement in modulus to density ratio of the boron fiber is almost six times that of any of the standard engineering materials, including steel, aluminum, molybdenum, and magnesium. This is advantageous in the prevention of microbuckling of the fibres in the matrix under compression. The extremely high stiffness of the graphite fibers makes possible a composite that is ideal for applications where precise pointing and tracking are required. These are well suited for strut assemblies, especially in space structures that are subject to a wide temperature range across them.