Vol. 38. No. I LAYERED COMPOSITES Figure 3. SEM micrograph of the polished cross-section of Al, O/Al,O,(m-ZrO2) laminated composite diamond paste and the edges were rounded during polishing operation. Four-point bend strength tests were conducted with upper and lower spans of 0.95 and 1.90 pectively, and a crosshead speed of 0.05 cm/min Fracture toughness(K,c) was determined by SENB method in monolithic compacts For microstructural analysis a light microscope and a scanning electron microscope(SEM) were used. Analyses were performed on polished or fracture surfaces Results and discussion The apparent viscosity of the studied slurries was found to be very low($12 MPas). The thickness of e zirconia-containing layers and alumina layers were kept at -100 um and -150 um respectively in all the laminates. No bubbles were observed in any of the fired plates The SEM micrograph of the AL2O3/AL2O3(ZrO2)are shown in Fig 3. As can be clearly observed a Al, O,+m-Zro Zro igure 4. Thermal expansion curve corresponding to the monolithic compact indicated in the figure