Sm-doped Gd2Zr2O7 thermal barrier coatings: Thermal expansion coefficient, structure and failure

The Gd2Zr2O7 ceramic material is a promising candidate for thermal barrier coatings. In this work, Sm-doped Gd2Zr2O7 coating was deposited by electron beam-physical vapor deposition. The Sm-doped Gd2Zr2O7 coating exhibits high thermal expansion coefficient and thermal shock lifetime at 1100 °C. The thickness of TGO layer is about 15 μm at the end. It was found that the spallation of coatings resulted from the cracks coalescence. The TGO broken played a dominant role in the failure process of the Sm-doped Gd2Zr2O7 coating. •The Sm-doped Gd2Zr2O7 coating was deposited by EB-PVD.•The TBCs exhibit high thermal expansion coefficient and thermal shock lifetime.•The formation and coalescence of cracks lead to the spallation of TBCs.