CORRELATING THE MECHANICAL-PROPERTIES OF A CONTINUOUS FIBER-REINFORCED CERAMIC-MATRIX COMPOSITE TO THE SLIDING RESISTANCE OF THE FIBERS

The sliding resistance of NICALON fibers (SiC) in a lithium aluminosilicate (LAS III) glass-ceramic matrix has been correlated with the mechanical properties of the composite. Push-down measurements of the sliding resistance for individual fibers show an order of magnitude increase when the ceramic composite is annealed in air for 4 h at 800-degrees-C. Such increases are correlated with a loss of toughness, a reduction in the ultimate strength, and an increase in the matrix cracking stress of the composite, as measured using tension tests and bend tests of bulk samples.