Tape casting of platelet-reinforced ceramics

A range of ceramics reinforced with alumina and silicon carbide platelets have been fabricated using tape casting and lamination. A high degree of alignment of the platelets is achieved by this process. The effect of platelet additions on strength and toughness depends on the actual system involved. For example, in MoSi2 reinforced with Al2O3 platelets, microplasticity controls the mechanical response and both strength and toughness are increased by the addition of platelets. In Al2O3 reinforced by SiC platelets however, strength is flaw-size controlled and platelets degrade the strength. Toughness enhancement in such systems is dependent on the development of weak interfaces which enable crack deflection and pull-out, and on the development of residual stresses which promote microcracking.