Impermeable thin AI2O3 overlay for TBC protection from sulfate and vanadate attack in gas turbines

Mao, Scott X.

University of Pittsburgh

关键词: Yttrium Oxides;    Vanadates;    Zirconium Oxides;    Sulfates;    Corrosive Effects;   

DOI  :  10.2172/850475
RP-ID  :  none
RP-ID  :  FC26-01NT41189
RP-ID  :  850475

美国|英语

来源: UNT Digital Library

【 摘 要 】

25 {micro}m and a 2 {micro}m thick Al{sub 2}O{sub 3} overlay were deposited by HVOF thermal spray and by sol-gel coating method, respectively, onto to the surface of YSZ coating. Indenter test was employed to investigate the spalling of YSZ with and without Al{sub 2}O{sub 3} overlay after hot corrosion. The results showed that Al{sub 2}O{sub 3} overlay acted as a barrier against the infiltration of the molten salt into the YSZ coating during exposure, thus significantly reduced the amount of M-phase of ZrO{sub 2} in YSZ coating. Thick Al{sub 2}O{sub 3} overlay will increase compressive stress and failure in TBC. During next reporting time, Al{sub 2}O{sub 3} overlay will be deposited on the YSZ surface by the composite-sol-gel route (CSG). Hot corrosion tests will be carried out on the TBC.