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| High Temperature Corrosion Resistance of Wet Grit Blasted AIP AlSiY Coating |
| LI Hanyun 1 , WANG Bo 1,2 , PENG Xin 3 , YANG Lin 4 , YUAN Fuhe 1 |
1. Technical Center, AECC Shenyang Liming Aeroengine Corporation Ltd., Shenyang 110043, China;
2. Beihang University, Beijing 100191, China;
3. Shenyang Area 2nd Military Representative Room of Air Force Equipment Department, Shenyang 110043, China;
4. Heat and Surface Treatments Factory, AECC Shenyang Liming Aeroengine Corporation Ltd., Shenyang 110043, China |
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Abstract AlSiY coating was deposited on the directionally solidified DZ22 superalloy using an arc ion plating technique in an aim to resolve or alleviate the high temperature corrosion damage of high pressure turbine blades for aero-engines and gas turbine engines. The attained results demonstrate that the AlSiY coating deposited and vacuum diffusion heat treated at a high temperature consists of an outer, an intermediate and a thin inner diffusion layer, which is typical of a high activity aluminide diffusion coating composed of the single β–NiAl intermetallic phase. The results of thermogravimetric analyses and examinations of cross sections demonstrated that the wet grit blasting process improves significantly the corrosion resistance of the AlSiY coating under salt film and hot-gas conditions. A thick oxide scale developed on the as-diffusion heat treated coating consists primarily of Al2O3 and NiAl2O4 corrosion products under salt film and hot-gas corrosion conditions, and most of the coating degenerated into the γ′–Ni3Al phase with some pores formed inside. Wet grit blasting of the heat treated AlSiY coating is desirable to promote the selective oxidation of aluminium, chromium elements and formation of a thin, denser alumina scale under both corrosion conditions, thereby enhance remarkably the high temperature corrosion resistance and prolong the service life of the arc ion plated AlSiY coating.
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2022, 
