In situ deposition behavior of SiO2 on YSZ-TBC-coated IN738LC during a burner rig test

► TEOS-SiO2 was in situ deposited on YSZ-TBC-coated IN738LC using a burner rig. ► TBC was spalled when coated with high feed rates of TEOS due to thermal mismatch. ► The coating covered the TBC surface to a thickness of ~ 5 μm smoothly, after then irregularly. ► The condition of 0.3 vol.% TEOS gave a smooth and homogenous SiO2 coating without humps.