Powder Selection in Cosintering Multi-layered Ceramic Functionally Graded Materials Based on the Densification Kinetics Curves

In the cosintering process to fabricate a multi-layered ceramic functionally graded material (FGM), the difference in the sintering behaviors among the layers can cause cracks or camber to form. One way to reduce the likelihood of cracks or camber in the FGM is to use powders with similar transient densification kinetics for a given set of sintering conditions. In this study, the densification kinetics characteristics of several alumina powder mixtures and zirconia powder mixtures were investigated using a thermomechanical analyzer (TMA). By comparing the densification data for the alumina and zirconia powder mixtures, a set of mixtures that exhibits a similar transient densification kinetics was found. Using this set of powders, a three-layered alumina/alumina + zirconia/zirconia FGM was successfully fabricated without cracks or camber.