Ceramic Preforms with 2D Regular Channels for Fabrication of Metal/Ceramic-Reinforced Composites

Aligned regular 2D channels were fabricated in alumina via two routes: soft metal and carbon fibers. The soft metal route was accomplished employing centrifugal forces to eject the molten metal from the green matrix. The carbon fiber route was accomplished by burning out the carbon fibers between 450 degrees C and 630 degrees C. In both methods, pressureless sintering followed, yielding the desired 2D channel profiles. Some porous preforms exhibited higher fracture strength than the solid specimens, and this has been attributed to the ability of the channels to reduce the population and distribution of cracks in the porous material.