Thin-slice fiber pushout and specimen bending in metallic matrix composite tests

For researchers interested in fiber pushout testing of MMC's (including intermetallic matrix composites), we have shown that • • Composites containing optically transparent fibers can be metal backplated using photolithographic techniques to provide a support with a hole size matching the fiber diameter. • • Computational results indicate that backplated specimens exhibit negligible specimen flexure during thin-slice fiber pushout testing. • • Results from thin-slice fiber pushout tests of three different sapphire-reinforced MMC's indicate that the interfacial shear strength values are the same regardless of whether the specimen was supported by the Ni backplate or by a hole 1.6 times the fiber diameter or by a groove 2 times the fiber diameter. Thus at least for fiber aspect ratios of ≥2 and groove width/specimen thickness ratios ≤2, specimen bending does not significantly affect the measured value of the average interfacial shear strength at maximum fiber push-out load in the MMC systems studied.