Hot corrosion behavior of Si modified aluminide coating with and without YSZ top layer on γ-TiAl alloy
Jiqiang Wang*, Xiang Qiu, Xinyu Cui, Tianying Xiong
Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
*Corresponding author: Jiqiang Wang: Tel: +86-024-83978827; E-mail: jqwang11s@imr.ac.cn
Abstract: A Si modified aluminide coating was prepared on γ-TiAl alloy by cold sprayed Al-20Si alloy coating and subsequent heat treatment. Then, a YSZ top layer was sprayed on to the surface of the Si modified aluminide coating by air plasma spray. Hot corrosion behavior of Si modified aluminide coating with and without YSZ top layer was conducted in Na2SO4 and Na2SO4+25wt.%NaCl molten salt at 900℃. The microstructure and phase of the coating before and after corrosion test were characterized by SEM and XRD. The results indicated that the Si modified aluminide coating with YSZ top layer showed better hot corrosion resistance compared to the coating without YSZ top layer, which resulted from the barrier effect of the YSZ layer.
Keywords: Si modified aluminide coating; YSZ layer; Hot corrosion behavior; γ-TiAl alloy