ABSTRACT
This chapter summarizes the tensile properties of state-of-the-art boron reinforced aluminum and titanium. The tensile modulus, strength, and ductility are all lower for transverse tensile tests than for longitudinal tensile tests. If filaments split in transverse tensile tests of composites at these same low stress levels, the load carrying cross section would be sharply reduced and severe stress concentrations would be introduced which would account for the observed low composite strength and ductility. Examination of transverse tensile fracture surfaces clearly establishes the degrading influence of filament splitting. The aluminum-titanium comparison which has been developed above is not consistent with the observed transverse tensile strengths in these composite systems. A rule-of-mixture type prediction of composite tensile strength would require knowledge of the stress-strain behavior of each component under the conditions it would experience in the composite. The strain hardening matrix can make a larger contribution to composite strength.
