AN ULTIMATE TENSILE-STRENGTH DEPENDENCE ON PROCESSING FOR CONSOLIDATED METAL-MATRIX COMPOSITES

The ultimate tensile strength (UTS) of metal and intermetallic matrix unidirectional composites can be significantly lower than expected from the rule of mixtures prediction. One possible explanation is that the fibers in the as-processed state are in a residual state of stress and in some cases are broken because of the inhomogeneous nature of the densification during manufacture. Three main results emerge from the effort to include the effect of this processing damage on the composite UTS. First is the development of a simple but accurate analytical version of Curtin's model for predicting the stress-strain response and UTS of this class of composites. Second is the generalization of Curtin's model to include both process induced fiber bending and fracture. Third is that the reduction in strength is a sensitive function of the consolidation conditions; thus a link is established between the quality of the composite and the conditions of its manufacture.