Al表面改性Si-HfO2/YbDS/GYYZO热/环境障涂层的抗CMAS腐蚀性能OA

The rising service temperature of aero-engine hot-section components makes calcium magnesium aluminum silicate(CMAS)corrosion a key failure mechanism for thermal/environmental barrier coatings(T/EBCs).The novel Gd2O3-Yb2O3-Y2O3 co-stabilized ZrO2(GYYZO)ceramic is promising due to its good thermophysical properties.However,its CMAS corrosion resistance at 1500℃needs improvement.In this work,a PS-PVD-fabricated Si-HfO2/Yb2Si2O7/GYYZO coating system was enhanced via Al deposition and vacuum heat treatment.Firstly,the as-sprayed coating was annealed at 1300℃to heal microcracks.Subsequently,a 3-4 μm thick aluminum film was deposited on the GYYZO layer surface via direct current pulsed magnetron sputtering.Finally,vacuum heat treatment(400℃/2.5 h+660℃/2 h+808℃/1.5 h+980℃/1 h)was conducted to promote the formation of a dense Al2O3 barrier layer.A comparative study at 1500℃revealed that CMAS rapidly penetrated the unmodified GYYZO coating along grain boundaries,causing blistering and cracking in the Yb2Si2O7 layer and accelerating failure.Conversely,the Al-modified GYYZO coating formed a dense Al2O3 barrier in situ,effectively suppressing CMAS penetration and slowing corrosion kinetics,thus maintaining structural integrity after 1 h.