Patent attributes
A tri-barrier ceramic coating system is provided having a base thermal barrier layer, an intermediate CMAS barrier layer, and a top erosion barrier layer, and the method of applying such a coating system to a substrate. The base layer has a typical columnar structure with inter-columnar gaps and intra-columnar micro-pores that provides the stress tolerance during thermal cycles. The intermediate CMAS barrier layer has the fiber-like columns with inter-columnar nano-pores and a grid structure on the bottom of the layer. The fine structured intermediate layer covers the gaps between the columns of the base layer and will block CMAS infiltration effectively. The top erosion resistant layer contains wider TBC columns with narrow inter-columnar gaps and a modified cauliflower-like TBC head that provides erosion resistance for the underlying layers. The tri-barrier coating microstructure will further reduce the thermal conductivity as comparing to the conventional single layer system.
