Effect of stacking pressure on the properties of Si3N4 ceramics fabricated by aqueous tape casting

Silicon nitride ceramics were successfully fabricated and the effect of stacking pressure on the structure and properties is discussed. The porosity of the green bodies decreased slightly with the stacking pressure after burning out process. High stacking pressure (>= 20 MPa) was necessary to avoid the de lamination in the green and sintered samples. Flexural strength decreased substantially with the decreasing of stacking pressure, but the fracture toughness decreased slightly. Elongated beta-Si3N4 grains linked the delaminated layers together and formed an inter-locked structure, which can be adjusted by stacking pressure and sintering process. Thus, controlling the stacking pressure and sintering process may be an effective way to obtain Si3N4 ceramics with high fracture toughness. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.