PREDICTION OF RESIDUAL'THERMAL STRESSES IN SHORT FIBER - METAL MATRIX COMPOSITES

Short fiber reinforced metal matrix composites ( SFRMMC ) were found to be attractive due to the high strength and stiffness, availability and processability at modest cost, machinability and workability, low weight, high temperature serviceability, and microstructure stability . Among the ( SFRMMC ), the aluminum alloys reinforced with silicon carbide whiskers represent an interesting class. They showed an improvement in strength, stiffness, fatigue and creep of fifty to one hundred percent over unreinforced alloys. A complete understanding of the mechanisms of strengthening and fracture in this class of composites have not yet been established, and a continued detailed studies are required. In the present study the residual thermal stress and strain patterns in the SiC (w) / 6061 Al composites were found to be non-uniform with compressive stresses in the whisker and tensile stresses in the matrix having higher values at the interface and peak values at the whisker end corners, leading to enhanced dislocation generation.