SiC fibre-reinforced LAS glass-ceramic via sol-gel technique

A modified process to fabricate Nicalon SiC fiber-reinforced LAS glass-ceramic composite is presented. This process combines the advantages of the slurry method and the pure sol-gel technique. The process offers the possibility to control the interface through the interpolation of interphase layers at the fiber/matrix boundary by fiber coatings and through changing the composition of the sol-gel solution. The results of tests on the bending strength, fracture toughness and shear stress of composites fabricated by the new process are reported. The interfacial structures which were investigated by transmission electron microscopy (TEM), selected-area diffraction (SAD) and electron energy loss spectroscopy (EELS), and the effect of the type of sol-gel solution on them, are described.