Engineering Techniques for the Control of Strength Reproducibility in Two Refractory Intermetallic Composites <xref rid="FN1" ref-type="fn">*</xref>

The feasibility of using ceramic materials for advanced airframe and propulsion system structural applications has already been demonstrated. However, their effective use is limited by their relatively high variability in strength. Although it is known that a large number of factors influences the strength of ceramic materials, in the two ceramic composite systems studied here, ZrB₂-SiC-B₄C and C-ZrB₂-SiC, it was apparent that each system had its own strength controlling parameters.

It was found that the strength variability could be noticeably decreased by incorporating two engineering techniques: (a) material selectivity, and (b) proof testing. It is shown that at the low probability failure rates normally associated with airframe structure design allowable strengths can be approximately doubled.